Added Submition validation for sync_plan tests.

Upon submission of any page, there is a chance that the validation
of data may fail and hence the entity creation too fails.

The idea is to check for the submit/create/save locators after the
submission of page. If these locators still exist on the page then
the validation fails.

Added a submit_validate flag so that we have a choice to validate
whether submission was successful. This needs to be used for all
the negative tests, as submission would always fail for them.

submit_validate flag is set to True by default.
Needs to be set to false for all negative tests.
Merge pull request #1737 from kbidarkar/submit_validate

Added Submition validation for sync_plan tests.
Sync plan locator fixes and increased the manifest upload timeout.

Uploading a manifest is too time consuming, hence the increase in
timeout.

Sync-plan related locators are now updated for the upstream builds.
Merge pull request #1743 from kbidarkar/locator-fixes

Sync plan locator fixes and increased the manifest upload timeout.