Subscribe for record function and if android do atrace (#28708)
Summary:
ghstack-source-id: 5edaf471557c25098ca0547229f2763760866887
Pull Request resolved: https://github.com/pytorch/pytorch/pull/28708
Some cpp formatting changes as I run `clang-format -i`
Testing on devserver:
make assets (models):
```
pushd android/test_app/; python make_assets.py; popd
```
Build test_app apk:
```
TRACE_ENABLED=1 sh android/build_test_app.sh
find . -type f -name *apk
./android/test_app/app/build/outputs/apk/mobNet2Quant/debug/test_app-mobNet2Quant-debug.apk
./android/test_app/app/build/outputs/apk/resnet18/debug/test_app-resnet18-debug.apk
```
Install apk:
`adb install -r test_app-mobNet2Quant-debug.apk`
Run app on the device.
Systrace:
```
$ANDROID_HOME/platform-tools/systrace/systrace.py -t 10 -a org.pytorch.testapp.mobNet2Quant sched freq idle am wm gfx view binder_driver hal dalvik camera input res -o trace.html
```
trace.html contains sections like `jni::Module::forward`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/28712
Differential Revision: D18495898
Pulled By: IvanKobzarev
fbshipit-source-id: 0bced4a442f9dd90525520972a2c1f5d51f57df3
