Hide IME first when clicking on area outside bubble

When IME is open and user taps on the area above the IME and outside the
bubble, dismiss the IME, but leave the bubble open.
When tapping on the area again, collapse the bubble.
Updated order of events when tapping outside the bubble or using back
gesture is:
1. close EDU if visible
2. close caption menu if visible
3. hide IME if visible
4. collapse bubble

Bug: 345483473
Flag: com.android.wm.shell.enable_bubble_bar
Test: open caption menu and IME, tap outside of bubble, caption menu
  closes, tap again, IME hides, tap again, bubble collapses
Change-Id: I82a0ed18929fa452f5d16e37492190d69b8f12a8