Modify EmbeddedWindow InputTarget to work with IME

EmbeddedWindow implements InputTarget to allow IME to work for embedded
windows. However, a few methods need to be modified to allow IME to
work.

1. shouldControlIme should return true if there's a host WindowState.
   This doesn't meant the embedded window will control the IME, but
   rather the host for embedded will control the IME. This is needed
   to ensure the IME is reparented to the correct Activity and uses
   the parent WindowState to when determining inset controller.

2. getImeControlTarget should return the host WindowState's control
   target. This ensures the IME has the correct target information and
   not the fallback.

3. getActivityRecord should return the host ActivityRecord. This tells
   IME where to reparent the layer so it's a child of the
   ActivityRecord. Othewise, the IME layer is left where it was
   previously.

Test: SurfaceControlViewHostTests
Bug: 230340812
Change-Id: I8407c3ec7ed6372ed3484f25117db45944855a22