Pause watchdog triggering on the main thread during OtaDexoptService

Similar to I3876c41e6d0e41d044a5b1d5e57f894c7fb4fb0e where we pause
the watchdog because dexopting can take a while, here moving A/B
artificats can take a long time.

Bug: 134062700
Test: Manually tested by adding an artificial sleep in
OtaDexoptService#main and verified that watchdog was not triggered

Change-Id: I69067fbbb8be4e421918c18b67269044fab51b3e