Remove generate_hashtree:true

It's true by default and we're deprecating generate_hashtree:false.

Change-Id: I6f0400393d0e673208623472236385203e96b414
Flag: EXEMPT refactor
Test: m (no changes)
Bug: 184914612
1 file changed
tree: 723c7901b7c6485c4c0b23e5f5c88f779c0abb44
  1. apex/
  2. OWNERS
  3. PREUPLOAD.cfg