Allow list literal to have ending comma.

For consistency with most languages. Before, something like "uint64_t[]
f = {1, 2, 3,}" would be an error because of the trailing comma.
However, now it works.

Bug: N/A (just optimizing workflow)
Test: aidl_unittests + run_integration_test.sh
Change-Id: I308e4c5aec0a97bc1fab8a7d11127d79b4ee83bc
3 files changed