Lower case the first letter of storage type.

In the app details, the first letter of the storage type was
capitalized, causing an odd string of "X used in Internal storage."

Change-Id: I2b4f23ea1799dc1730fdab596e4a87a0cb673c68
Fixes: 36001265
Test: Settings robotest

src/com/android/settings/applications/InstalledAppDetails.java

@@ -712,7 +712,7 @@ public class InstalledAppDetails extends AppInfoBase
                     ? R.string.storage_type_external
                     : R.string.storage_type_internal);
             return context.getString(R.string.storage_summary_format,
-                    getSize(context, stats), storageType);
+                    getSize(context, stats), storageType.toString().toLowerCase());
         }
     }