SystemUI: Alpha tuning in recents

* Equalized the Alpha's in Constants
* Reduced Fade in and Fade outs at 1/5

Change-Id: I834b50fe5ab4a4cbd527f36346f61bf2d27203e2
Increased the amount of document visible in Recent Documents

* Visible upto 100 recent documents
Change-Id: I4c1f921f85b7afa995db690c9d829a8d961b0437
Merge changes I4c1f921f,I834b50fe into pac-4.4

* changes:
  Increased the amount of document visible in Recent Documents
  SystemUI: Alpha tuning in recents