Enable vendors to organize ImeContainer

Add FEATURE_IME as unique id for ImeContainer to organize it from
WmShell.
Disable automatic ImeContainer surface and container reparenting when
it is organized.

These changes enable vendors to control where the IMEs are positioned
and implement custom UX rules (e.g. for foldable devices - place the
IME on the bottom screen while the focused app is on the top one).

Manual test:
Organize FEATURE_IME from WmShell.
Set its bounds, appBounds, screenSizeDp and setSmallestScreenWidthDp.
Outcome:
* The IME receives onConfigurationChanges.
* The IME is updated on the screen.
* The IME is not reparented from its default parent.

Test: atest WmTests:WindowProcessControllerTests
Test: atest WmTests:DisplayContentTests
Test: atest WmTests:WindowContainerTests
Test: atest WmTests:DisplayAreaTest
Test: atest WmTests:DualDisplayAreaGroupPolicyTest
Bug: 188038793

Change-Id: I438253e9647ceab5b7847b8db66db8399271723f