cmsdk: Actually return the system property in Build.

TICKET: CYNGNOS-2379
Change-Id: I7c7f3726b34db2b26d63fb4ef95df469fdf7e989
diff --git a/api/cm_current.txt b/api/cm_current.txt
index 9d8a981..758315e 100644
--- a/api/cm_current.txt
+++ b/api/cm_current.txt
@@ -566,8 +566,8 @@
   public class Build {
     ctor public Build();
     method public static java.lang.String getNameForSDKInt(int);
-    field public static final java.lang.String CYANOGENMOD_DISPLAY_VERSION = "ro.cm.display.version";
-    field public static final java.lang.String CYANOGENMOD_VERSION = "ro.cm.version";
+    field public static final java.lang.String CYANOGENMOD_DISPLAY_VERSION;
+    field public static final java.lang.String CYANOGENMOD_VERSION;
     field public static final java.lang.String UNKNOWN = "unknown";
   }
 
diff --git a/sdk/src/java/cyanogenmod/os/Build.java b/sdk/src/java/cyanogenmod/os/Build.java
index e758413..5d53213 100644
--- a/sdk/src/java/cyanogenmod/os/Build.java
+++ b/sdk/src/java/cyanogenmod/os/Build.java
@@ -28,10 +28,10 @@
     public static final String UNKNOWN = "unknown";
 
     /** A build ID utilized to distinguish cyanogenmod versions */
-    public static final String CYANOGENMOD_VERSION = "ro.cm.version";
+    public static final String CYANOGENMOD_VERSION = getString("ro.cm.version");
 
     /** A build ID string meant for displaying to the user */
-    public static final String CYANOGENMOD_DISPLAY_VERSION = "ro.cm.display.version";
+    public static final String CYANOGENMOD_DISPLAY_VERSION = getString("ro.cm.display.version");
 
     private static final SparseArray<String> sdkMap;
     static
@@ -168,4 +168,8 @@
         }
         return name;
     }
+
+    private static String getString(String property) {
+        return SystemProperties.get(property, UNKNOWN);
+    }
 }
diff --git a/system-api/cm_system-current.txt b/system-api/cm_system-current.txt
index 9d8a981..758315e 100644
--- a/system-api/cm_system-current.txt
+++ b/system-api/cm_system-current.txt
@@ -566,8 +566,8 @@
   public class Build {
     ctor public Build();
     method public static java.lang.String getNameForSDKInt(int);
-    field public static final java.lang.String CYANOGENMOD_DISPLAY_VERSION = "ro.cm.display.version";
-    field public static final java.lang.String CYANOGENMOD_VERSION = "ro.cm.version";
+    field public static final java.lang.String CYANOGENMOD_DISPLAY_VERSION;
+    field public static final java.lang.String CYANOGENMOD_VERSION;
     field public static final java.lang.String UNKNOWN = "unknown";
   }