Implement property_get() for the compatibility library.

Bug: 10315692

This change also allows us to remove the dependency on libcutils for the
compatibility library. The implementation is the exact version that is in
libcutils.

Change-Id: If285962d6631cf9ca1030718c436e122f9be1d4f
diff --git a/rsContext.cpp b/rsContext.cpp
index 74c40c5..dd795a6 100644
--- a/rsContext.cpp
+++ b/rsContext.cpp
@@ -34,10 +34,14 @@
 #include <dlfcn.h>
 #include <unistd.h>
 
-#if !defined(RS_SERVER)
+#if !defined(RS_SERVER) && !defined(RS_COMPATIBILITY_LIB)
 #include <cutils/properties.h>
 #endif
 
+#ifdef RS_COMPATIBILITY_LIB
+#include "rsCompatibilityLib.h"
+#endif
+
 #ifdef RS_SERVER
 // Android exposes gettid(), standard Linux does not
 static pid_t gettid() {