Init ProcessState w/ initWithDriver.

vndservicemanager was calling 'self' before 'initWithDriver':
ProcessState::self()->initWithDriver(...);

However, 'self' inits the driver. On devices with the VNDK, this caused
no problem because libbinder automatically inits to the correct driver
node. However, on legacy devices, vndservicemanager tried to use
/dev/binder unsuccessfully.

Bug: 137216568
Test: TH
Change-Id: I8dc9dac0592784a16ae0abd270718ae353aa81c3