Always check VNDK variant identicalness

Previously, we only check VNDK core and vendor variants are identical
when a VNDK library is not declared to have different variants AND the
target has TARGET_VNDK_USE_CORE_VARIANT set.  Therefore, it is fairly
easily to break a TARGET_VNDK_USE_CORE_VARIANT target as it needs to be
tested explicitly.

This change uses the new LOCAL_CHECK_SAME_VNDK_VARIANTS and expands the
check to run regardless of TARGET_VNDK_USE_CORE_VARIANT.  Also adds
support for VNDK-in-product.

Bug: 145157349
Test: Build success for targets with and without
      TARGET_VNDK_USE_CORE_VARIANT.
Test: With the corresponding change in build/make, remove libbinder
      from build/soong/cc/config/vndk.go and check build fails even
      when TARGET_VNDK_USE_CORE_VARIANT is not set.

Change-Id: Iec708b971072e6580f77a03e243b30b89b3b054d
diff --git a/tools/check_identical_lib.sh b/tools/check_identical_lib.sh
index 01007c0..c3aa41a 100755
--- a/tools/check_identical_lib.sh
+++ b/tools/check_identical_lib.sh
@@ -5,11 +5,13 @@
 CORE="${2}"
 VENDOR="${3}"
 
-stripped_core="${CORE}.vndk_lib_check.stripped"
-stripped_vendor="${VENDOR}.vndk_lib_check.stripped"
+TMPDIR="$(mktemp -d ${CORE}.vndk_lib_check.XXXXXXXX)"
+stripped_core="${TMPDIR}/core"
+stripped_vendor="${TMPDIR}/vendor"
 
 function cleanup() {
-  rm -f ${stripped_core} ${stripped_vendor}
+  rm -f "${stripped_core}" "${stripped_vendor}"
+  rmdir "${TMPDIR}"
 }
 trap cleanup EXIT