[429682] Replace Multimap with Map<String, Collection<String>>

Replace usages of Guava's Multimap<String, String> in ViewpointSelection
public methods by Map<String, Collection<String>>. The implementation is
kept the same, we just use Multimap's asMap() method to avoid exposing
the Guava-specific type.

Bug: 429682
Change-Id: I4ed7a87faf942734048699c2608c591266a426eb
Signed-off-by: Pierre-Charles David <pierre-charles.david@obeo.fr>
4 files changed