Switch to new CPU UID time readers

Switch to new per-UID CPU concurrent active, concurrent cluster, and
per-frequency time readers added in ag/5516062, used to read CPU times
info from the kernel via proc files in order to calculate per-UID CPU
power consumption.

These readers acquire constant amount of memory space during the first
read, thus do not leave garbage over time. Also, they read the text
version of these CPU time proc files, instead of the binary version
introduced in P, encouraging all kernels to implement a standard
human-readable CPU time proc interface:
* /proc/uid_time_in_state
* /proc/uid_concurrent_active_time
* /proc/uid_concurrent_policy_time
* /proc/uid_cputime/show_uid_stat

Remove old readers that read the binary version, since they are no
longer in use.

Bug: 111216804
Test: atest FrameworksCoreTests:com.android.internal.os.BatteryStatsTests
Test: verified that it works end to end. BatteryStats dumpsys output is
      similar to proc file output.
Change-Id: Iaa1321e1facabece1c777eaeb79187cf081436ae