Switch to GameActivity and gradle build

Fixes: https://github.com/damus-io/notedeck/issues/189
Fixes: https://github.com/damus-io/notedeck/issues/190
Signed-off-by: William Casarin <jb55@jb55.com>

.gitignore

@@ -2,9 +2,13 @@
 build.log
 perf.data
 perf.data.old
+crates/notedeck_chrome/android/app/build
 .privenv
+*.so
 *.swp
+*.jar
 target
+.gradle
 queries/damus-notifs.json
 .git
 cache
@@ -17,4 +21,4 @@ scripts/macos_build_secrets.sh
 *.txt
 /tags
 *.mdb
-.idea/
+.idea/