Reduce libhwbinder API surface (1/?).

Removed in this round:
- All Vector'ed read/write methods
- Reading/writing dup native_handles
- Blob/ashmem support
- Special binder transactions (ping, dump, interface)
- Various unused helpers.

Obvious remaining items that require more work:
- writeString16()/writeCString() and read variants
- writeInterface() / enforceInterface()

Test: hidl_test
Change-Id: Ica2bbbdee469f12c797d9f3feff6046b2337de6a
8 files changed