hwc2: Fix Hwc2Test.SET_VSYNC_ENABLED_no_callback_no_power

When no callback is registered, the hwcomposer2 header specifies
that no error should be returned, if the vsync is attempted to be
enabled. This may happen, for example, with virtual displays.

CRs-Fixed: 2028964
Change-Id: I43f6f0d2b0541bac9e2f380e7846cc00611627a8
2 files changed