simpleperf: fix reading kernel modules on Android.

1. Load kernel modules in specified places on Android.
2. Read the size of each loaded module from /proc/modules.
3. Adjust the way to find symbols in kernel/kernel modules accordingly.

Bug: None.
Test: run simpleperf record on walleye.
Test: run simpleperf_unit_test.
Change-Id: I6f6cac2734a94c70b5bbe7c5367966a0afa8efea
2 files changed