Rename power_stat_hal to power_stats

This is a simple file rename to allow to make subsequent review easier.

Bug: 182927513
Change-Id: Ia6c3f07a427c23e79877a75c3201b518c659b44b
diff --git a/Android.bp b/Android.bp
index d0eb9b0..838eb79 100644
--- a/Android.bp
+++ b/Android.bp
@@ -620,8 +620,8 @@
     "src/android_internal/atrace_hal.cc",
     "src/android_internal/health_hal.cc",
     "src/android_internal/incident_service.cc",
+    "src/android_internal/power_stats.cc",
     "src/android_internal/power_stats_aidl.cc",
-    "src/android_internal/power_stats_hal.cc",
     "src/android_internal/statsd_logging.cc",
     "src/android_internal/tracing_service_proxy.cc",
   ],