Introduce helper method to determine device type

Based on the front and back camera sensor types, use
the system property to distinguish between FP3 and FP3+.

Issue: PRJ8901-1318
Issue: PRJ8901-1551
Issue: FP3-A11#233
Change-Id: I1d96182221742c33ea2fb0b5b4001120efdf963e
(cherry picked from commit 337c49d89c716f2e1ca9d1a676da4b006840bb49)
diff --git a/core/java/android/os/Build.java b/core/java/android/os/Build.java
index 018bb2c..64c6cbc 100755
--- a/core/java/android/os/Build.java
+++ b/core/java/android/os/Build.java
@@ -29,6 +29,7 @@
 import android.sysprop.TelephonyProperties;
 import android.text.TextUtils;
 import android.util.Slog;
+import android.util.Log;
 import android.view.View;
 
 import dalvik.system.VMRuntime;
@@ -1296,6 +1297,18 @@
     @SystemApi
     public static final boolean PERMISSIONS_REVIEW_REQUIRED = true;
 
+    /** {@hide} */
+    public static String getFairphoneModel() {
+        String backCamera = getString("persist.vendor.camera.back");
+        String frontCamera = getString("persist.vendor.camera.front");
+        String pcba = getString("ro.boot.pcbastage");
+        return backCamera.equals("S5KGM1SP_TXD")
+                && frontCamera.equals("S5K3P9SP_TXD")
+                && pcba.contains("8903")
+            ? "FP3+"
+            : "FP3";
+    }
+
     /**
      * Returns the version string for the radio firmware.  May return
      * null (if, for instance, the radio is not currently on).