Do not send initial natively sized frame of HeaderSubview from HT to ST

When setting subviews via `setOptions` from `useEffect` hook in a
component, the first frame received might be computed by native
layout & completely invalid (zero height). RN layout is the source of a
subview **size** (not origin). When we send such update with zero height
Yoga might (or might not, depending on exact update timing in relation
to other ongoing commits / layouts) set the subview height to 0!
This causes the subview to become invisible & we want to avoid that.

This had not been a problem before #2696, because we would filter out
this kind of frame in the `setSize` guard in the
`ComponentDescriptor.adopt` method of the `HeaderSubview`. #2696 allowed
for zero-sized frames for other, unrelated reason & we must allow these
  as long as they come from React Native layout & not native one.

Author: kkafar

android/src/main/java/com/swmansion/rnscreens/ScreenStackHeaderSubview.kt

@@ -10,6 +10,14 @@ class ScreenStackHeaderSubview(
 ) : FabricEnabledHeaderSubviewViewGroup(context) {
     private var reactWidth = 0
     private var reactHeight = 0
+
+    /**
+     * Semantics: true iff we **believe** that SurfaceMountingManager has measured this view during mount item
+     * execution. We recognize this case by checking measure mode in `onMeasure`. If Androidx
+     * happens to use `EXACTLY` for both dimensions this property might convey invalid information.
+     */
+    private var isReactSizeSet = false
+
     var type = Type.RIGHT
 
     val config: ScreenStackHeaderConfig?
@@ -22,9 +30,10 @@ class ScreenStackHeaderSubview(
         if (MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY &&
             MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.EXACTLY
         ) {
-            // dimensions provided by react
+            // dimensions provided by react (with high probability)
             reactWidth = MeasureSpec.getSize(widthMeasureSpec)
             reactHeight = MeasureSpec.getSize(heightMeasureSpec)
+            isReactSizeSet = true
             val parent = parent
             if (parent != null) {
                 forceLayout()
@@ -44,7 +53,15 @@ class ScreenStackHeaderSubview(
         if (changed && BuildConfig.IS_NEW_ARCHITECTURE_ENABLED) {
             val width = r - l
             val height = b - t
-            updateSubviewFrameState(width, height, l, t)
+
+            // When setting subviews via `setOptions` from `useEffect` hook in a component, the first
+            // frame received might be computed by native layout & completely invalid (zero height).
+            // RN layout is the source of subview **size** (not origin) & we need to avoid sending
+            // this native size to ST. Doing otherwise might lead to problems.
+            // See: TODO: PR LINK
+            if (isReactSizeSet) {
+                updateSubviewFrameState(width, height, l, t)
+            }
         }
     }