profiling: Add management for system properties.

Change-Id: I6dea624542b3429086d4641a5fa91032a97709d1
diff --git a/Android.bp b/Android.bp
index 4eb1891..6e4f684 100644
--- a/Android.bp
+++ b/Android.bp
@@ -58,6 +58,7 @@
     "src/profiling/memory/main.cc",
     "src/profiling/memory/record_reader.cc",
     "src/profiling/memory/socket_listener.cc",
+    "src/profiling/memory/system_property.cc",
     "src/profiling/memory/unwinding.cc",
     "src/profiling/memory/wire_protocol.cc",
     "src/protozero/message.cc",
@@ -2299,6 +2300,8 @@
     "src/profiling/memory/sampler_unittest.cc",
     "src/profiling/memory/socket_listener.cc",
     "src/profiling/memory/socket_listener_unittest.cc",
+    "src/profiling/memory/system_property.cc",
+    "src/profiling/memory/system_property_unittest.cc",
     "src/profiling/memory/unwinding.cc",
     "src/profiling/memory/unwinding_unittest.cc",
     "src/profiling/memory/wire_protocol.cc",