Undo the Extensions API version change

Because most of the dependent features are not yet ready, revert it back
in T_QPR1.

Bug: 247950006
Test: pass existing
Change-Id: I451cb0d640f935c542a0e79df8c08945d5c4776c

libs/WindowManager/Jetpack/src/androidx/window/extensions/WindowExtensionsImpl.java

@@ -41,7 +41,7 @@ public class WindowExtensionsImpl implements WindowExtensions {
     // TODO(b/241126279) Introduce constants to better version functionality
     @Override
     public int getVendorApiLevel() {
-        return 2;
+        return 1;
     }
 
     /**