Fix per app GPS power usage.

After GPS power profile changed from a single value "gps.on" to a
"gps.signalqualitybased" array, we use the time gps stays in each
signal level to calculate the average gps power usage.

Bug: 79379255
Test: adb shell dumpsys batterystats, looking for "gps=" in per app
power usage section.

Change-Id: I93d17d5bd25324cc9f36a7a5502b088a44184621