Add requiredSystemPropertyValue support in idmap2

Up to Android P, there was this feature were we are able to
define "requiredSystemPropertyValue" in the AndroidManifest.xml
of the RRO apk, so that it will only be loaded if
requiredSystemPropertyValue/requiredSystemPropertyName are matched.

Porting support from idmap
https://android.googlesource.com/platform/frameworks/base/+/master/cmds/idmap/scan.cpp#135

To idmap2
https://android.googlesource.com/platform/frameworks/base/+/master/cmds/idmap2/idmap2/Scan.cpp#175

Bug: 140891738
Change-Id: I47752af93efa4563a60e336c1e1b1ffc081b51ec
diff --git a/cmds/idmap2/libidmap2/ResourceUtils.cpp b/cmds/idmap2/libidmap2/ResourceUtils.cpp
index 71ba3f0..dce83e3 100644
--- a/cmds/idmap2/libidmap2/ResourceUtils.cpp
+++ b/cmds/idmap2/libidmap2/ResourceUtils.cpp
@@ -103,6 +103,16 @@
     info.priority = std::stoi(iter->second);
   }
 
+  iter = tag->find("requiredSystemPropertyName");
+  if (iter != tag->end()) {
+    info.requiredSystemPropertyName = iter->second;
+  }
+
+  iter = tag->find("requiredSystemPropertyValue");
+  if (iter != tag->end()) {
+    info.requiredSystemPropertyValue = iter->second;
+  }
+
   return info;
 }