title: GC overhead limit exceeded when building android source
body: <pre>****[ 35% 11837/33004] build out/target/common/obj/JAVA_LIBRARIES/sdk_v21_intermediates/classes.jack <br/>
  FAILED:/bin/bash -c <br/>"<br/>(mkdir -p out/target/common/obj/JAVA_LIBRARIES/sdk_v21_intermediates/) <br/>&& (java <b>-Xmx3500m</b> -jar out/host/linux-x86/framework/jill.jar --output out/target/common/obj/JAVA_LIBRARIES/sdk_v21_intermediates/classes.jack.tmpjill.jack prebuilts/sdk/21/android.jar) <br/>&& (mkdir -p out/target/common/obj/JAVA_LIBRARIES/sdk_v21_intermediates/classes.jack.tmpjill.res) <br/>&& (unzip -qo prebuilts/sdk/21/android.jar -d out/target/common/obj/JAVA_LIBRARIES/sdk_v21_intermediates/classes.jack.tmpjill.res) <br/>&& (find out/target/common/obj/JAVA_LIBRARIES/sdk_v21_intermediates/classes.jack.tmpjill.res -iname \"*.class\" -delete) <br/>&& (JACK_VERSION=2.26.RELEASE out/host/linux-x86/bin/jack @build/core/jack-default.args --verbose error -D jack.import.resource.policy=keep-first -D jack.import.type.policy=keep-first --import out/target/common/obj/JAVA_LIBRARIES/sdk_v21_intermediates/classes.jack.tmpjill.jack --import-resource out/target/common/obj/JAVA_LIBRARIES/sdk_v21_intermediates/classes.jack.tmpjill.res --output-jack out/target/common/obj/JAVA_LIBRARIES/sdk_v21_intermediates/classes.jack) <br/>&& (rm -rf out/target/common/obj/JAVA_LIBRARIES/sdk_v21_intermediates/classes.jack.tmpjill.res) <br/>&& (rm out/target/common/obj/JAVA_LIBRARIES/sdk_v21_intermediates/classes.jack.tmpjill.jack)<br/>"
  GC overhead limit exceeded
  Try increasing heap size with java option '-Xmx'
  Warning: This may have produced partial or corrupted output.
  [ 35% 11837/33004] Building with Jack: out/target/common/obj/JAVA_LIBRARIES/core-all_intermediates/with-local/classes.dex
  FAILED: /bin/bash out/target/common/obj/JAVA_LIBRARIES/core-all_intermediates/with-local/classes.dex.rsp
  Communication error with Jack server (52)
  ninja: build stopped: subcommand failed.
  build/core/ninja.mk:139: recipe for target 'ninja_wrapper' failed
  make: *** [ninja_wrapper] Error 1****</pre>
  
  <p>This is the error message where the building process stopped, it says try to increase heap size with java option "-Xmx",but I do not know how to config it when building the android source.</p>