Temporariliy disable predictive back in fragments

Disabling predictive back transitions by default in fragments to avoid
causing any issues internally.

Test: all existing tests pass
Change-Id: I6664b75005508f4f25a91207bb99775bffd06b97

diff --git a/fragment/fragment/src/main/java/androidx/fragment/app/FragmentManager.java b/fragment/fragment/src/main/java/androidx/fragment/app/FragmentManager.java
index 59c47e5..5c393da 100644
--- a/fragment/fragment/src/main/java/androidx/fragment/app/FragmentManager.java
+++ b/fragment/fragment/src/main/java/androidx/fragment/app/FragmentManager.java

@@ -116,7 +116,7 @@
     @RestrictTo(RestrictTo.Scope.LIBRARY)
     public static final String TAG = "FragmentManager";
 
-    static boolean USE_PREDICTIVE_BACK = true;
+    static boolean USE_PREDICTIVE_BACK = false;
 
     /**
      * Control whether FragmentManager uses the new state predictive back feature that allows