Collects binder call stats data through WestWorld.

We require binder calls detailed tracking to be enabled to collect the
stats (in addition to enabling it in WestWorld).

Test: unit test + manual

adb shell cmd stats pull-source 10022
Pull from 10022: { 1531240941000000000 25807560798 (10022)0x10000->0[I]
0x20000->com.android.server.StorageManagerService$3[S]
0x30000->onVolumePathChanged[S] 0x40000->1[L] 0x50000->0[L]
0x60000->18490[L] 0x70000->18490[L] 0x80000->2611[L] 0x90000->2611[L]
0xa0000->0[L]  } ...

Change-Id: I07cad5d8678426cdac45872cda028ea7a85d7d81