Docker driver only supports LinuxBridge networking

Added an admonition highlighting that the Docker driver only supports
LinuxBridge networking.

Change-Id: Iff14a0046350dad044c9e26fad0149571a9cb3ce
Closes-Bug: #1243319
Fixing path

Change-Id: I2407c26ef9ec83a5286f336c83bd2eaa750d0873
Merge "Fixing path"
Merge "Docker driver only supports LinuxBridge networking"