Support RTL in Stack

Test: layout/foundation/framework/material tests passed; rtl test for
Stack
Bug: 146346559
Relnote: "Stack component supports right-to-left directionality"
Change-Id: Ic9e00dfc5b8c16ff305c14bc38de38cdf72d4cf5

diff --git a/ui/ui-layout/src/androidTest/java/androidx/ui/layout/test/IntrinsicTest.kt b/ui/ui-layout/src/androidTest/java/androidx/ui/layout/test/IntrinsicTest.kt
index 889c2f7..7373dd4 100644
--- a/ui/ui-layout/src/androidTest/java/androidx/ui/layout/test/IntrinsicTest.kt
+++ b/ui/ui-layout/src/androidTest/java/androidx/ui/layout/test/IntrinsicTest.kt

@@ -51,7 +51,7 @@
         val childSize = Ref<IntPxSize>()
         val childPosition = Ref<PxPosition>()
         show {
-            Align(alignment = Alignment.TopLeft) {
+            Align(alignment = Alignment.TopStart) {
                 OnChildPositioned( coordinates ->
                     minIntrinsicWidthSize.value = coordinates.size
                     positionedLatch.countDown()
@@ -82,7 +82,7 @@
         val childSize = Ref<IntPxSize>()
         val childPosition = Ref<PxPosition>()
         show {
-            Align(alignment = Alignment.TopLeft) {
+            Align(alignment = Alignment.TopStart) {
                 OnChildPositioned( coordinates ->
                     minIntrinsicHeightSize.value = coordinates.size
                     positionedLatch.countDown()
@@ -113,7 +113,7 @@
         val childSize = Ref<IntPxSize>()
         val childPosition = Ref<PxPosition>()
         show {
-            Align(alignment = Alignment.TopLeft) {
+            Align(alignment = Alignment.TopStart) {
                 OnChildPositioned( coordinates ->
                     maxIntrinsicWidthSize.value = coordinates.size
                     positionedLatch.countDown()
@@ -144,7 +144,7 @@
         val childSize = Ref<IntPxSize>()
         val childPosition = Ref<PxPosition>()
         show {
-            Align(alignment = Alignment.TopLeft) {
+            Align(alignment = Alignment.TopStart) {
                 OnChildPositioned( coordinates ->
                     maxIntrinsicHeightSize.value = coordinates.size
                     positionedLatch.countDown()
@@ -175,7 +175,7 @@
         val childSize = Ref<IntPxSize>()
         val childPosition = Ref<PxPosition>()
         show {
-            Align(alignment = Alignment.TopLeft) {
+            Align(alignment = Alignment.TopStart) {
                 ConstrainedBox(DpConstraints(maxWidth = 5.dp)) {
                     OnChildPositioned( coordinates ->
                         minIntrinsicWidthSize.value = coordinates.size
@@ -208,7 +208,7 @@
         val childSize = Ref<IntPxSize>()
         val childPosition = Ref<PxPosition>()
         show {
-            Align(alignment = Alignment.TopLeft) {
+            Align(alignment = Alignment.TopStart) {
                 ConstrainedBox(DpConstraints(minWidth = 15.dp)) {
                     OnChildPositioned( coordinates ->
                         minIntrinsicWidthSize.value = coordinates.size
@@ -241,7 +241,7 @@
         val childSize = Ref<IntPxSize>()
         val childPosition = Ref<PxPosition>()
         show {
-            Align(alignment = Alignment.TopLeft) {
+            Align(alignment = Alignment.TopStart) {
                 OnChildPositioned( coordinates ->
                     minIntrinsicHeightSize.value = coordinates.size
                     positionedLatch.countDown()
@@ -274,7 +274,7 @@
         val childSize = Ref<IntPxSize>()
         val childPosition = Ref<PxPosition>()
         show {
-            Align(alignment = Alignment.TopLeft) {
+            Align(alignment = Alignment.TopStart) {
                 OnChildPositioned( coordinates ->
                     minIntrinsicHeightSize.value = coordinates.size
                     positionedLatch.countDown()
@@ -307,7 +307,7 @@
         val childSize = Ref<IntPxSize>()
         val childPosition = Ref<PxPosition>()
         show {
-            Align(alignment = Alignment.TopLeft) {
+            Align(alignment = Alignment.TopStart) {
                 OnChildPositioned( coordinates ->
                     maxIntrinsicWidthSize.value = coordinates.size
                     positionedLatch.countDown()
@@ -340,7 +340,7 @@
         val childSize = Ref<IntPxSize>()
         val childPosition = Ref<PxPosition>()
         show {
-            Align(alignment = Alignment.TopLeft) {
+            Align(alignment = Alignment.TopStart) {
                 OnChildPositioned( coordinates ->
                     maxIntrinsicWidthSize.value = coordinates.size
                     positionedLatch.countDown()
@@ -373,7 +373,7 @@
         val childSize = Ref<IntPxSize>()
         val childPosition = Ref<PxPosition>()
         show {
-            Align(alignment = Alignment.TopLeft) {
+            Align(alignment = Alignment.TopStart) {
                 OnChildPositioned( coordinates ->
                     maxIntrinsicHeightSize.value = coordinates.size
                     positionedLatch.countDown()
@@ -406,7 +406,7 @@
         val childSize = Ref<IntPxSize>()
         val childPosition = Ref<PxPosition>()
         show {
-            Align(alignment = Alignment.TopLeft) {
+            Align(alignment = Alignment.TopStart) {
                 OnChildPositioned( coordinates ->
                     maxIntrinsicHeightSize.value = coordinates.size
                     positionedLatch.countDown()