Build prebuilt policy with Soong

... and remove redundant Makefile codes. This also updates commit hook
as we now only use Soong to build sepolicy.

Bug: 296875906
Test: m selinux_policy
Change-Id: I93f0d222a0c10e31c51c9380780a8927c47d62b1
diff --git a/tools/Android.mk b/tools/Android.mk
deleted file mode 100644
index 34f4385..0000000
--- a/tools/Android.mk
+++ /dev/null
@@ -1,3 +0,0 @@
-LOCAL_PATH:= $(call my-dir)
-
-include $(call all-makefiles-under,$(LOCAL_PATH))
diff --git a/tools/policy_version_check.sh b/tools/policy_version_check.sh
index 33ce861..f82c53d 100755
--- a/tools/policy_version_check.sh
+++ b/tools/policy_version_check.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-MK=$(awk -F= '/POLICYVERS/ { print $2 }' policy_version.mk | tr -d ' [:space:]')
+MK=$(awk -F= '/PolicyVers/ { print $2 }' build/soong/policy.go | tr -d ' [:space:]')
 BP=$(awk -F= '/DSEPOLICY_VERSION/ { print $2 }' Android.bp | awk -F\" ' { print $1 }')
 
 if [ "$MK" != "$BP" ]; then