Android: changes the JNI generator to use long by default.

BUG=317523

Review URL: https://codereview.chromium.org/131883002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249461 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249461