Remove call to postToView

Calling collectFlow has the same effect, so it is not necessary. The
call is the last one outside the shade package, so this allows us to
remove it from the interface.

Bug: 303267342
Flag: NONE
Test: Manual and presubmits
Change-Id: I69a29fa3f6b4c9520351e114ae9fcb52a0eebc67