Ensure insets state for dispatch is processed by policy

Otherwise the visibility of transient state doesn't take effect if
there is a fixed rotation insets state. Then the client side may not
aware visibility change to update alpha of insets leash.

Bug: 160458371
Test: atest DisplayPolicyLayoutTests#testFixedRotationInsetsSourceFrame
  InsetsStateControllerTest#testTransientVisibilityOfFixedRotationState

Change-Id: Icecb25f64e983b163f169c191a9f0b15ac1b3086
Merged-In: Icecb25f64e983b163f169c191a9f0b15ac1b3086