Switch assistant to HEAVY_CLICK effect on devices without haptic composition.

EFFECT_DOUBLE_CLICK is used for REJECT situations so it
feels like a mistake. EFFECT_HEAVY_CLICK was used for
EDGE_SQUEEZE previously so it's a better choice anyway.

Bug: 182381083
Fixes: 186767913
Test: long-press power
Change-Id: Iea474367a3f09a842b644cff7e2e2f05d6ddac49

services/core/java/com/android/server/policy/PhoneWindowManager.java

@@ -5153,7 +5153,7 @@ public class PhoneWindowManager implements WindowManagerPolicy {
                             .compose();
                 }
                 // fallback for devices without composition support
-                return VibrationEffect.get(VibrationEffect.EFFECT_DOUBLE_CLICK);
+                return VibrationEffect.get(VibrationEffect.EFFECT_HEAVY_CLICK);
 
             default:
                 return null;