Automation scripts for perf testing (#28622)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/28622
### Summary
As discussed in #28405 , this is the third PR. The`bootstrap.sh` script is mainly for those who want to do perf on iOS but don't want to touch XCode or any iOS code. But it does require you have valid iOS dev credentials installed on your machine. (You can easily acquire those stuff from any experienced iOS developers. Takes only 5 mins to setup )
All you need to do is run
```shell
./bootstrap -t ${TEAM_ID} -p ${PROFILE}
```
The testing app will be automatically installed on your device. The log of the benchmark function will be displayed on the screen.
### Test plan
Don't break any CI jobs unless they're flaky.
Test Plan: Imported from OSS
Differential Revision: D18156178
Pulled By: xta0
fbshipit-source-id: cd7ba8d87bf26db885262888b9d6a5fd072309d1
