mdPanel: Ability to modify the duration of a mdPanelAnimation

[bradrich]

Actual Behavior:

• What is the issue? *
• Within the current mdPanelAnimation API, there is no way to modify the duration of the chosen animation.
• What is the expected behavior?
• There are currently three built-in animations that can be used: SLIDE, SCALE, and FADE. There is, however, no way to modify the duration of the animation. Adding the duration will allow for the animation to be faster or slower than the default 0.3s.

CodePen (or steps to reproduce the issue): *

• CodePen Demo which shows your issue: N/A
• Details: N/A

Angular Versions: *

• Angular Version: Latest
• Angular Material Version: Latest

Additional Information:

• Browser Type: * All
• Browser Version: * All
• OS: * All
• Stack Traces: All

Ping @ErinCoughlan.