compat: libhidlbase: add shim for missing constructor map symbol

gBn/sConstructorMap symbols were removed from libhidl:
- https://android.googlesource.com/platform/system/libhidl/+/e29b2ad

However, some prebuilts still make use of them.

In some cases, for example when using GSI, libhidl can not be patched
directly, which requires modifying affected blobs to depend on this shim
library.

Change-Id: I097c75ac210a9c3f50a9725da0b910d819c85b9a
Signed-off-by: Alexander Martinz <amartinz@shiftphones.com>

Android.bp

@@ -322,6 +322,14 @@ cc_library {
     vendor: true,
 }
 
+cc_library {
+    name: "libhidlbase_shim",
+    srcs: ["libhidlbase/gBnsConstructorMap.cpp"],
+    shared_libs: ["libhidlbase"],
+    compile_multilib: "both",
+    vendor: true,
+}
+
 cc_library {
     name: "libmemset_shim",
     target: {

libhidlbase/gBnsConstructorMap.cpp

@@ -0,0 +1,15 @@
+#include <hidl/Static.h>
+
+namespace android {
+namespace hardware {
+namespace details {
+
+// Deprecated; kept for ABI compatibility. Use getBnConstructorMap.
+DoNotDestruct<BnConstructorMap> gBnConstructorMap{};
+
+// Deprecated; kept for ABI compatibility. Use getBsConstructorMap.
+DoNotDestruct<BsConstructorMap> gBsConstructorMap{};
+
+} // namespace details
+} // namespace hardware
+} // namespace android