Compile HalfSheetUX against framework-connectivity-t.impl

HalfSheetUX uses private apis of framework-connectivity-t. It appears
that using just "framework-connectivity-t" will compile against either
the stubs or source of framework-connectivity-t depending on if the
module was included in the same apex as it or not.

aosp/2462194 is adding the ability to compile modules like HalfSheetUX
outside of the context of the apex, at which point it will start
compiling against stubs if we don't explicetly specify to use the
implementation library.

Bug: 254205429
Test: m javac-check with aosp/2462194
Change-Id: I1d41e47aa0e4e3d320b78b28cfc181fc30c4537c
Merged-In: I1d41e47aa0e4e3d320b78b28cfc181fc30c4537c