heif: add HeifWriter for writing heif still images

Currently supports three types of sources:
YUV byte buffer, Surface, or Bitmaps. Number of images must
be specified upfront (as muxer will not allow track addition
after start). Also, all still images must be of the same
format.

bug: 63633199

Change-Id: I9700e657fcd036908a94b53c55091f87679e0c11

diff --git a/settings.gradle b/settings.gradle
index c030172..ed8e779 100644
--- a/settings.gradle
+++ b/settings.gradle

@@ -45,6 +45,7 @@
 includeProject(":drawerlayout", "drawerlayout")
 includeProject(":exifinterface", "exifinterface")
 includeProject(":gridlayout-v7", "v7/gridlayout")
+includeProject(":heifwriter", "heifwriter")
 includeProject(":interpolator", "interpolator")
 includeProject(":jetifier-core", "jetifier/jetifier/core")
 includeProject(":jetifier-gradle-plugin", "jetifier/jetifier/gradle-plugin")