display: Fix dependency compile error

When enforce compile time product I/F, system_ext module
cannot link to product module and vice versa.
When PRODUCT_PRODUCT_VNDK_VERSION := current, all native modules
in product partition are in the product variant. Adding system_ext_specific
and vendor_available will create system_ext variant and vendor variant.
This will fix the following dependency compile 2 errors:
-Error: MMCapability.cpp:33:10: fatal error: 'qd_utils.h' file not found
libwfdsinksm.so [MMCapability.cpp], installed in SYSTEM_EXT partition
and depends on libqdMetaData [qd_utils.h], accessable in product partition.
Replacing product_specific with system_ext_specific, while enforcing product I/F
will install libqdMetaData in system_ext and variant in product partition

-Error: dependency "libgralloc.qti" of "libqdMetaData" missing variant
libqdMetaData now moved to system_ext. Need to install libgralloc.qti
in system_ext.

Change-Id: Ic4eb768173f2125cee2bb1fa69665b50e8708ea5
diff --git a/gralloc/Android.bp b/gralloc/Android.bp
index 0ec61ac..4882e79 100644
--- a/gralloc/Android.bp
+++ b/gralloc/Android.bp
@@ -1,7 +1,7 @@
 cc_library_shared {
     name: "libgralloc.qti",
     vendor_available: true,
-    product_specific: true,
+    system_ext_specific: true,
     cflags: [
         "-Wno-sign-conversion",
         "-DLOG_TAG=\"qtigralloc\"",
diff --git a/libqdmetadata/Android.bp b/libqdmetadata/Android.bp
index 449d46a..7621800 100644
--- a/libqdmetadata/Android.bp
+++ b/libqdmetadata/Android.bp
@@ -1,7 +1,7 @@
 cc_library_shared {
     name: "libqdMetaData",
     vendor_available: true,
-    product_specific: true,
+    system_ext_specific: true,
     cflags: [
         "-Wno-sign-conversion",
         "-DLOG_TAG=\"qdmetadata\"",