Fix ViewPager calling onPageScrolled(0)

This CL fixes the situation of ViewPager dispatching
onPageScrolled(0) just because it has not been laid out,
and thus populated. The call makes no sense in this
state anyway.

BUG: 28110875
Change-Id: I54e552ffc5355e2e6c59c4e2c7a9d28393b47ac1
1 file changed