Sharesheet - Fix layouts for multi-window mode

When using multi-mode and holding the phone in portrait, android will
report it's orientation as LANDSCAPE. Take multi-window mode into
account when determining fixed widths as well as number of items per
row.

Bug: 132828939
Test: Use multi-window mode
Change-Id: I97b722ea58c9f79aea2a3ab594c3ad7d78f8607c