Use display specific context for caption inset calculation

They height of the caption inset is specific to each display, so use the
context of display the task is targeting to retrieve caption height
value that corresponds to that display.

Flag: com.android.window.flags.exclude_caption_from_app_bounds
Test: atest DesktopModeLaunchParamsModifierTests,
      atest WMShellUnitTests:DesktopTasksControllerTest
      & manual testing
Bug: 416336612
Change-Id: I16c62ae8d4d6c5bc6ead13922c09aab73311f046