SF: Reconfirm all period changes, ignore HWC

This change includes two separate fixes to make waking up from idle more
robust when using a kernel idle timer:

  1) Always reconfirm the refresh rate when we resync to hardware vsync.
     This is because if the kernel idle timer is enabled, we may not
     immediately be in the refresh rate we expect to be.
  2) Ignore the refresh rate reported by the hardware vsync callbacks,
     since that refresh rate may not reflect the actual refresh rate
     when the kernel idle timer is in effect.

Bug: 154303580
Test: systrace
Test: libsurfaceflinger_unittest
Change-Id: I79c66faeaed262acd9c5925fe2202a9fb3f10b7b