frontend: Fix findbugs method doesn't start with lower case

Fix findbugs method doesn't start with a lower case letter error in
frontend SearchableListModel class methods Search, AsyncSearch,
SyncSearch

Change-Id: Ibf8aff3c66801c9c64856ccdbceeee48203628d0
Signed-off-by: Tal Nisan <tnisan@redhat.com>