keystore2: Use libbinder_rs Strong references for Binder objects

Update keystore2 to use libbinder_rs Strong<> and Weak<> references for
Binder objects rather than just Box<dyn Interface>.

Bug: 175584883
Test: atest keystore2_test
Change-Id: Ic234ce5ed007a265769a72043d77eb817a21b8ea
12 files changed