Add BatteryStatsViewer to GS101-based userdebug and eng builds

Bug: 185952656
Test: build, flash, verify that BatteryStatsViewer is in the app list

Change-Id: I1fbbd21908d515027125aae6b3b7f27a1cd075d5
diff --git a/device.mk b/device.mk
index 92190f6..833a2e3 100644
--- a/device.mk
+++ b/device.mk
@@ -1133,3 +1133,7 @@
 
 # Pixel Logger
 include hardware/google/pixel/PixelLogger/PixelLogger.mk
+
+# Battery Stats Viewer
+PRODUCT_PACKAGES_DEBUG += BatteryStatsViewer
+