Adapt to Jack compilation specifics.
Fix bad import in VideoDumpActivity.
The extra semicolumn is ignored by javac because of
https://bugs.openjdk.java.net/browse/JDK-8027682 but is not
permitted by ecj or Jack.
This includes cherry-picks of the following changes:
248ef6f9c414db26fd1bc7ec3d4ee4f3b87d54cf
705555dc468e46560d02db102dfcedc1e5c70d9e
f50a51fb4c8d5ca973ce910a21bddf9f8466cb51
bf5ad8d9943c0e1b0b3f1b4524c277f369065d08
Change-Id: Ifbe063e3822a7d63b1681921b9788cfca898ba64
7bcaf9a997