brillo: Remove dependency on java for Brillo

Brillo does not require Java. Add a JAVA_NOT_REQUIRED
flag to the build system to make the jdk requirment optional

Also don't build signapk for Brillo

BUG: 25281898
Change-Id: I31e68cc7d076bf6c234699c77c0ea1ea428be4f5
2 files changed