Revert nested-type-args

This reverts two changes:
- I969a4ca7a16f6fcd49348d766792c6b40b004c01
- Ic29f265ea7d89754d006102d5bc912a3c4058252

The reason:
- The fix was a hack relying on the fact const_expr starts with '='.
But, in fact, const_expr appears annotation parameters, which makes it
available wherever annotation is available. At least it
might restrict the language change in the future.
- We need more robust and solid solution rather than a hack.

Until then we need to insert an extra space between '>' and '>'.

  Foo<Bar<Baz> > foo;

Bug: 171946195
Test: aidl_unittests
Change-Id: I20c3a29d383afaf91f29cb835560fc8d84dfbc18
2 files changed