Add betterbug folder to gs-common

Better Bug was previously labeled as priv_app, here we kept the same 'type=privapp_data_file levelFrom=user'

Copied some Better Bug used rules from system/sepolicy/private/priv_app.te.
(https://source.corp.google.com/h/googleplex-android/platform/superproject/main/+/main:system/sepolicy/private/priv_app.te;l=1?q=priv_app.te)

Test: local test
Bug: 322543833
Change-Id: Ia029e855dd46e65b9eec31835ccaabb3cb903058
diff --git a/betterbug/betterbug.mk b/betterbug/betterbug.mk
new file mode 100644
index 0000000..f3ae647
--- /dev/null
+++ b/betterbug/betterbug.mk
@@ -0,0 +1,5 @@
+PRODUCT_PACKAGES += BetterBugStub
+PRODUCT_PACKAGES_DEBUG += BetterBug
+
+PRODUCT_PUBLIC_SEPOLICY_DIRS += device/google/gs-common/betterbug/sepolicy/product/public
+PRODUCT_PRIVATE_SEPOLICY_DIRS += device/google/gs-common/betterbug/sepolicy/product/private