Migrate SurfaceFlingerProps into sysprop_library

SurfaceFlinger will use sysprop_library for properties.

Bug: 112386364
Test: m -j && boot taimen
Change-Id: I81f3c9a27733b6f9de3fcd7dd1fbf829f821ccdb
diff --git a/services/surfaceflinger/sysprop/api/current.txt b/services/surfaceflinger/sysprop/api/current.txt
new file mode 100644
index 0000000..d802177
--- /dev/null
+++ b/services/surfaceflinger/sysprop/api/current.txt
@@ -0,0 +1 @@
+// Signature format: 2.0