Fix VtsHalVibratorManagerTargetTest test fail

Adding the cancelSynced() once prepareSynced() was called and return ok.

Fix: 247687286
Test: atest VtsHalVibratorManagerTargetTest
Signed-off-by: Chase Wu <chasewu@google.com>
Change-Id: I91e08e92cb8e1399eb6acdbedf95958fbf44c393
1 file changed