Just use the GitHub icons. Here's the assets folder for the official GitHub Android app including the TTF font. The license is pretty permissive.
Assuming you have a TextView
with the id text
and the TTF file in your assets folder, you can do something like this:
TextView text = (TextView) findViewById(R.id.text);
text.setText("Clone \uf04c");
text.setTypeface(Typeface.createFromAsset(getAssets(), "octicons-regular-webfont.ttf"));