SPARK-3009: Reverted readObject method in ApplicationInfo so that Applic...

...ationInfo is initialized properly after deserialization

Author: Jacek Lewandowski <lewandowski.jacek@gmail.com>

Closes #1947 from jacek-lewandowski/master and squashes the following commits:

713b2f1 [Jacek Lewandowski] SPARK-3009: Reverted readObject method in ApplicationInfo so that ApplicationInfo is initialized properly after deserialization

(cherry picked from commit a75bc7a21db07258913d038bf604c0a3c1e55b46)
Signed-off-by: Andrew Or <andrewor14@gmail.com>