Use ProcessState::selfOrNull in ServiceManager APIs

Allow the APIs to be used when ProcessState isn't initialized.
This allows the use of these APIs in systems like microdroid where there
is no kernel binder driver.

Test: atest vm_accessor_test
Bug: 358427181
Change-Id: Ie981b0ca4335ddc7a5676d30721c01be1ffdf35e
2 files changed