setFrameRate: Make shouldBeSeamless an enum

Change the shouldBeSeamless parameter to an enum
in order to make the API easier to understand.

This changes
 - SurfaceControl.setFrameRate
 - Surface.setFrameRate
 - ANativeWindow_setFrameRateWithChangeStrategy
 - ASurfaceTransaction_setFrameRateWithChangeStrategy

Bug: 179116474
Test: atest SetFrameRateTest
Change-Id: I55265399238e2c95fbb90fd33a4c2513d1fc5cec