Allow customization of touch handler.

Add #setTouchHandler to PipManager so that other devices (e.g. TV,
Chrome OS) may set its own touch handler to overwrite the default one.

Bug: 148407130
Test: Set a custom touch handler, note it being used instead of the
default one

Change-Id: Ice3a57a700926b474b29dec1e0b3a8503501477b
diff --git a/packages/SystemUI/src/com/android/systemui/pip/phone/PipManager.java b/packages/SystemUI/src/com/android/systemui/pip/phone/PipManager.java
index f39d1ec..e48a23f 100644
--- a/packages/SystemUI/src/com/android/systemui/pip/phone/PipManager.java
+++ b/packages/SystemUI/src/com/android/systemui/pip/phone/PipManager.java
@@ -297,6 +297,13 @@
     }
 
     /**
+     * Sets a customized touch gesture that replaces the default one.
+     */
+    public void setTouchGesture(PipTouchGesture gesture) {
+        mTouchHandler.setTouchGesture(gesture);
+    }
+
+    /**
      * Sets both shelf visibility and its height.
      */
     @Override