Don't render page actions when none exist

Flow pages (See I1646fc495c4e120f823ae77a33454364f30fea13) and
any page which kills all page actions should not render the menu at
all. This avoids an unnecessary gray line.

Change-Id: I24672b7d52035118c43580341243f7479621dc74
Merge "Don't render page actions when none exist"