Move HIDL calls away from the main thread

class_init is running under application main thread. A sequence
of 10 back to back HIDL calls is a power up vulnerability, as
watchdog may kick in if application main thread is taking too
long.

Bug: 63707763
Fixes: 63707763
Test: Tested on Taimen and verified GPS works.
Change-Id: Ia8833e7bc5f2bd6186c1f74f84c5387640cc44df