Disable accessibility state changes of the focused view for Android API < 21

Summary:
This diff disables accessibility state changes of the focused view for Android API < 21.
This is necessary because the method view.isAccessibilityFocused was introduced in Android API 21
Users in Android API < 21 will not be able to hear accessibility state changes of the focused view (feature introduced by D17903205)

Changelog: disables accessibility state changes of the focused view for Android API < 21, see PR: 26624

Reviewed By: fkgozali

Differential Revision: D19199096

fbshipit-source-id: 12b349f0ac94b77e9e7328ae40e1ae1a278e8b24

Author: mdvacca

ReactAndroid/src/main/java/com/facebook/react/uimanager/BaseViewManager.java

@@ -8,6 +8,7 @@
 package com.facebook.react.uimanager;
 
 import android.graphics.Color;
+import android.os.Build;
 import android.text.TextUtils;
 import android.view.View;
 import android.view.ViewParent;
@@ -173,7 +174,8 @@ public void setViewState(@NonNull T view, @Nullable ReadableMap accessibilitySta
               && accessibilityState.getType(STATE_CHECKED) == ReadableType.String)) {
         updateViewContentDescription(view);
         break;
-      } else if (view.isAccessibilityFocused()) {
+      } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP
+          && view.isAccessibilityFocused()) {
         // Internally Talkback ONLY uses TYPE_VIEW_CLICKED for "checked" and
         // "selected" announcements. Send a click event to make sure Talkback
         // get notified for the state changes that don't happen upon users' click.