Allow nullable locking directory in SupportSQLiteLock.

Some family and mostly older devices don't properly create the cache directory and a null value can be returned by the context, to protect from such case the lock directory for process locking a database is not obligatory and the behaviour will fallback as it used to before the process lock, i.e. only in-memory locking.

Bug: 265353349
Test: Existing
Change-Id: I13f5e6253afa33bdea69559b40f43298123cbb0d
(cherry picked from commit on android-review.googlesource.com host: 265124d30f61f6c46ad967c6b55f6c34dffe7899)
Merged-In: I13f5e6253afa33bdea69559b40f43298123cbb0d

diff --git a/sqlite/sqlite-framework/src/main/java/androidx/sqlite/util/ProcessLock.kt b/sqlite/sqlite-framework/src/main/java/androidx/sqlite/util/ProcessLock.kt
index 3b79342..dc07eb9 100644
--- a/sqlite/sqlite-framework/src/main/java/androidx/sqlite/util/ProcessLock.kt
+++ b/sqlite/sqlite-framework/src/main/java/androidx/sqlite/util/ProcessLock.kt

@@ -52,12 +52,12 @@
 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 class ProcessLock(
     name: String,
-    lockDir: File,
+    lockDir: File?,
     private val processLock: Boolean
 ) {
-    private val lockFile: File = File(lockDir, "$name.lck")
+    private val lockFile: File? = lockDir?.let { File(it, "$name.lck") }
     @SuppressLint("SyntheticAccessor")
-    private val threadLock: Lock = getThreadLock(lockFile.absolutePath)
+    private val threadLock: Lock = getThreadLock(name)
     private var lockChannel: FileChannel? = null
 
     /**
@@ -69,6 +69,9 @@
         threadLock.lock()
         if (processLock) {
             try {
+                if (lockFile == null) {
+                    throw IOException("No lock directory was provided.")
+                }
                 // Verify parent dir
                 val parentDir = lockFile.parentFile
                 parentDir?.mkdirs()