powerstats: use gs common library to get common data providers

Bug: 206576142
Test: dumpsys android.hardware.power.stats.IPowerStats/default
Change-Id: I894196858441352be5e403fcb2f0461300b5217e
Signed-off-by: Darren Hsu <darrenhsu@google.com>

powerstats/Android.bp

@@ -15,7 +15,7 @@
 soong_namespace {
     imports: [
         "hardware/google/pixel",
-        "device/google/gs201",
+        "device/google/gs201/powerstats",
     ]
 }