[1/n] Introduce API for all available max WindowMetrics

New API provides all maximum WindowMetrics, for all
possible rotations in each DeviceState. This information
allows launcher apps to determine different device
layouts ahead of time, without having to reload the
grid model on every device state change (fold/unfold).

Done:
* WindowManager calculates bounds for the given display, in
  possible rotations
* Defining API surface

Not started:
* WindowManager calculates insets for each rotation
* Display stack builds collection of DisplayInfo, for all
  possible display states (folded, unfolded)
* Display stack pushing set of DisplayInfos to WindowManager

Bug: 181127261
Test: atest FrameworksCoreTests:WindowMetricsTest
Test: atest FrameworksCoreTests:WindowInsetsTest
Change-Id: Ic4580f9c1ee919e5e93cd96b8f11c743fa42f9f1