Migrate from InsetsInfo.contentInsets to WindowManager.LayoutParams#providedInternalInsets

- This allows us to distinguish taskbar's ITYPE_EXTRA_NAVIGATION_BAR insets from its ITYPE_BOTTOM_TAPPABLE_ELEMENT insets
- Set nav bar insets as before (contentInsets)
- Set tappable elements insets the same, except when taskbar is stashed, in which case set to 0

Test: TaplTestsTaskbar; manually stash/unstash taskbar, open IME, open Calculator (which uses tappableElement() insets) and Contacts (which uses systemBars())
Fixes: 215411414
Change-Id: If00f7a590b0780715d5b8159f5135054364ce84e

quickstep/src/com/android/launcher3/taskbar/StashedHandleViewController.java

@@ -176,7 +176,8 @@ public class StashedHandleViewController implements TaskbarControllers.LoggableT
         return revealAnim;
     }
 
-    public void onIsStashed(boolean isStashed) {
+    /** Called when taskbar is stashed or unstashed. */
+    public void onIsStashedChanged(boolean isStashed) {
         mRegionSamplingHelper.setWindowVisible(isStashed);
         if (isStashed) {
             mStashedHandleView.updateSampledRegion(mStashedHandleBounds);