Handle simplified Slice deep link intent pattern.

Old intent:
settings://com.android.settings.slices?intent=android-app%3A%2F%2Fcom.android.settings%23Intent%3Baction%3Dcom.android.settings.action.VIEW_SLICE%3BS.slice%3Dcontent%253A%252F%252Fcom.android.settings.slices%252Faction%252Fscreen_magnification_navbar_preference_screen%3B

New intent:
settings://com.android.settings.slices?slice%3Dcontent%253A%252F%252Fcom.android.settings.slices%252Faction%252Fscreen_magnification_navbar_preference_screen%3B

Change-Id: Ia786812c68b5a2b1858203f62494c0d5f5a4a5ba
Fixes: 110156445
Test: manual