Split out some miscellaneous utility functions

* We also wrap up and cache the fetching of friendly names by serial
  number to avoid some adb traffic.

renderdoc/android/android_utils.h

@@ -46,4 +46,9 @@ enum class ToolDir
 };
 std::string getToolPath(ToolDir subdir, const std::string &toolname, bool checkExist);
 bool toolExists(const std::string &path);
+
+std::string GetFriendlyName(std::string deviceID);
+bool CheckRootAccess(const std::string &deviceID);
+bool SearchForAndroidLibrary(const std::string &deviceID, const std::string &location,
+                             const std::string &layerName, std::string &foundLayer);
 };