fix: keep BackgroundDrawable creation lazy, propagate bounds instead

Revert the eager ensureBackgroundDrawable call inside setBorderRadius
so views with borderRadius but no backgroundColor don't carry an
always-allocated drawable. Instead, fix the root timing issue at the
actual site of the bug: when ensureBackgroundDrawable lazily
constructs a new BackgroundDrawable + new composite, carry the
existing composite's bounds over before assigning view.background.
This primes the new drawable with the view's real dimensions so its
first draw computes the border-radius path correctly, without
imposing cost on views that never hit this path.

Test Plan: same RNTester repro (UI > Border > "Border radius with
transparent -> opaque background").

Author: janicduplessis

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/BackgroundStyleApplicator.kt

@@ -211,14 +211,9 @@ public object BackgroundStyleApplicator {
         compositeBackgroundDrawable.borderRadius ?: BorderRadiusStyle()
     compositeBackgroundDrawable.borderRadius?.set(corner, radius)
 
-    // Eagerly create the BackgroundDrawable so subsequent backgroundColor
-    // changes can mutate the existing drawable in place instead of
-    // replacing view.background with a freshly-constructed composite whose
-    // inner BackgroundDrawable has 0x0 bounds on first draw. Without this,
-    // a backgroundColor transition from transparent to opaque leaves the
-    // view rendering as a rectangle even though borderRadius is set.
-    // See https://github.com/facebook/react-native/issues/52415.
-    ensureBackgroundDrawable(view)
+    if (view is ImageView) {
+      ensureBackgroundDrawable(view)
+    }
     compositeBackgroundDrawable.background?.borderRadius = compositeBackgroundDrawable.borderRadius
     compositeBackgroundDrawable.backgroundImage?.borderRadius =
         compositeBackgroundDrawable.borderRadius
@@ -642,7 +637,16 @@ public object BackgroundStyleApplicator {
               compositeBackgroundDrawable.borderRadius,
               compositeBackgroundDrawable.borderInsets,
           )
-      view.background = compositeBackgroundDrawable.withNewBackground(background)
+      val newComposite = compositeBackgroundDrawable.withNewBackground(background)
+      // Carry the existing composite's bounds over so the freshly
+      // constructed BackgroundDrawable has the view's real dimensions when
+      // it first draws. Without this, setBackgroundColor called after the
+      // view has been laid out (e.g. a transparent -> opaque transition)
+      // would leave the drawable with 0x0 bounds on its first draw and the
+      // border-radius path would collapse to a rectangle.
+      // See https://github.com/facebook/react-native/issues/52415.
+      newComposite.bounds = compositeBackgroundDrawable.bounds
+      view.background = newComposite
       background
     }
   }