Adding all sources to a "_all" pseudo module fixes Studio's code analysis
functions (imports, refactoring).

In order to have things build properly in gradle, the "_all" module has
all sources excluded (gradle applies the filters, studio does not).

Also fix "--all" targets to include tests. Make it easier to make sweeping
java refactors in Android Studio.

BUG=620034

Review-Url: https://codereview.chromium.org/2812133003
Cr-Commit-Position: refs/heads/master@{#465700}