Rail Power Monitor Addition for wifi

Change specifies a new wifi metric to be collected. There is a new power
monitor tool that will be for pre-production devices. With this monitor
it will better tell us what the power usage of the wifi subsystem
without having to estimate based off of the batter.

Bug: 115929961
Test: adb shell dumpsys batterystats
Results Examples:
        Energy consumed by wifi (mAh): 2.419736388888889
        Energy Rails consumed by wifi (mAh): 2.762777777777778

Change-Id: I14971e03d37dbabbb276d6c9ca717859f112165d
diff --git a/proto/src/wifi.proto b/proto/src/wifi.proto
index ad0ed8b..ee3777d 100644
--- a/proto/src/wifi.proto
+++ b/proto/src/wifi.proto
@@ -1424,6 +1424,9 @@
 
   // Amount of time wifi is scanning (ms)
   optional int64 scan_time_ms = 12;
+
+  // Actual monitored rail energy consumed by wifi (mAh)
+  optional double monitored_rail_energy_consumed_mah = 13;
 }
 
 // Metrics for Wifi Wake