[Compose] Small fix and gone for MotionLayout (#506)

* [Compose] Small fix and gone for MotionLayout

We should not have a default LayoutInformationReceiverFlag that is not
None.

Gone is now animated as expected in MotionLayout.

Added Example with test.

* Delete empty file

Author: oscar-ad

constraintlayout/compose/src/main/java/androidx/constraintlayout/compose/ConstraintLayout.kt

@@ -668,7 +668,7 @@ internal abstract class EditableJSONLayout(@Language("json5") content: String) :
     private var forcedHeight: Int = Int.MIN_VALUE
     private var forcedDrawDebug: MotionLayoutDebugFlags = MotionLayoutDebugFlags.UNKNOWN
     private var updateFlag: MutableState<Long>? = null
-    private var layoutInformationMode: LayoutInfoFlags = LayoutInfoFlags.BOUNDS
+    private var layoutInformationMode: LayoutInfoFlags = LayoutInfoFlags.NONE
     private var layoutInformation = ""
     private var last = System.nanoTime()
     private var debugName : String? = null

constraintlayout/compose/src/main/java/androidx/constraintlayout/compose/MotionLayout.kt

@@ -701,6 +701,7 @@ internal class MotionMeasurer : Measurer() {
         state.reset()
         constraintSet.applyTo(state, measurables)
         state.apply(root)
+        root.children.fastForEach { it.isAnimated = true }
         applyRootSize(constraints)
         root.updateHierarchy()
 

projects/ComposeConstraintLayout/app/build.gradle

@@ -62,6 +62,7 @@ dependencies {
     implementation "androidx.activity:activity-compose:1.3.0"
 
     implementation "androidx.compose.material:material:$compose_version"
+    implementation "androidx.compose.material:material-icons-extended:$compose_version"
     implementation "androidx.compose.ui:ui:$compose_version"
     implementation "androidx.compose.ui:ui-unit:$compose_version"
     implementation "androidx.compose.ui:ui-util:$compose_version"