use vector<uint8_t> for byte[] in AIDL

In native world, byte stream is typically represented in uint8_t[]
or vector<uint8_t>. C++ backend already generates that way. This
change involves NDK backend.

Now NDK backend also uses vector<uint8_t> just like C++ backend.

Bug: 144957764
Test: atest CtsNdkBinderTestCases
Merged-In: I8de348b57cf92dd99b3ee16252f56300ce5f4683
Change-Id: I8de348b57cf92dd99b3ee16252f56300ce5f4683
(cherry picked from commit 90703184)

Exempt-From-Owner-Approval: cp from internal