Add recovery_available property to sysprop module

This is required for a sysprop module to be used by a module like the
init which is available both in core and recovery variants.

Test: m
Change-Id: I075428289f5bdce26e931ccf3262793ca6e4a0fd

sysprop/sysprop_library.go

@@ -42,9 +42,10 @@ type syspropLibraryProperties struct {
 }
 
 type commonProperties struct {
-	Srcs             []string
+	Srcs               []string
-	Recovery         *bool
+	Recovery           *bool
-	Vendor_available *bool
+	Recovery_available *bool
+	Vendor_available   *bool
 }
 
 var (