Make the Android SDK install directory consistent (#1702)

In some places it was /usr/lib and in others it was /usr/local. I believe it should be /usr/local for 'user' based installs

Author: map7

docs/start/ns-setup-linux.md

@@ -67,10 +67,10 @@ Complete the following steps to set up NativeScript on your Linux development ma
 
 5. Install the [Android SDK](http://developer.android.com/sdk/index.html).
  1. Go to [Android Studio and SDK Downloads](https://developer.android.com/sdk/index.html#Other) and in the **SDK Tools Only** section download the package for Linux at the bottom of the page.
- 2. After the download completes, unpack the downloaded archive into a folder, such as `/usr/lib/android/sdk`
+ 2. After the download completes, unpack the downloaded archive into a folder, such as `/usr/local/android/sdk`
  * The archive you just extracted was the `tools` folder, so in this case it would be at: `/usr/local/android/sdk/tools`
  3. Set the ANDROID_HOME environment variable. Open `~/.bashrc` and add the following:
- <pre><code class="language-terminal">export ANDROID_HOME="/usr/lib/android/sdk/"
+ <pre><code class="language-terminal">export ANDROID_HOME="/usr/local/android/sdk/"
  export PATH="${PATH}:${ANDROID_HOME}tools/:${ANDROID_HOME}platform-tools/"</code></pre>
  4. In a text file which was opened, paste in the path to your variable (at the new line).