SF: fix wouldPresentEarly when allow_n_vsyncs_in_targeter=true

wouldPresentEarly should return true if the previous frame would
not cause a backpressure.

Bug: 308858993
Test: SF unit tests
Flag: com.android.graphics.surfaceflinger.flags.allow_n_vsyncs_in_targeter
Change-Id: I0035145e06f2782cc190e329b542c2f4bbd6f0f1
2 files changed