simpleperf: add view_the_profile.md.

This makes viewing-the-profile section of go/gmm-profiling externally
visible, with a few changes:
1. Use com.example.android.displayingbitmaps as the profile example.
2. Add instructions to build FlameScope before running FlameScope.
3. Add example of opening trace files in Android Studio.
4. Add simpleperf report command and custom report interface sections.

Bug: 203559486
Test: none
Change-Id: Iab87869ecc1eb9f3c073d3ec758866a5059e9d8e
14 files changed