Adding checks for broken bottleneck files (#7131)

* Adding checks for broken bottleneck files

An exception is raised when a broken cached bottleneck files is read. Such a file can be created as a result of sudden system failure. This commit refers the issue #2296

* handling broken bottleneck files by recreating

The patch detects the broken bottleneck files (might be created as a result of sudden system shut down) and recreates them if required.

* minor changes for broken bottleneck handling

Reverting some part of code for bottleneck handling changes

* Resolved indentation errors

This commit refers to the issue #2296

* Indentation issue for broken bottleneck script

This commit refers to pull request #7131 and issue #2296