Constrain content width in RemoteEdgeButton

Add fillMaxWidth to the inner RemoteRow in RemoteEdgeButton so that
its content is bounded by the button width. This ensures that the
existing TextConfiguration (with ellipsis and maxLines) can wrap
and ellipsize text to the button bounds.

Add a multi-line sample and preview with differing line lengths.

Bug: 548535872
Test: ./gradlew :wear:compose:remote:remote-material3:test
Relnote: "N/A"
TAG=agy
CONV=e8f72d45-2831-4608-83f7-a72cf2bae2a4

Change-Id: I8f20b3ce2c7f2430bdfaf801555ba155141d42b0