store/post: fix searching for phrases in postgres (#17042)

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

store/searchtest/post_layer.go

@@ -345,6 +345,11 @@ func testSearchExactPhraseInQuotes(t *testing.T, th *SearchTestHelper) {
 	require.NoError(t, err)
 	_, err = th.createPost(th.User.Id, th.ChannelBasic.Id, "channel test 123", "", model.POST_DEFAULT, 0, false)
 	require.NoError(t, err)
+	_, err = th.createPost(th.User.Id, th.ChannelBasic.Id, "channel something test 1 2 3", "", model.POST_DEFAULT, 0, false)
+	require.NoError(t, err)
+	_, err = th.createPost(th.User.Id, th.ChannelBasic.Id, "channel 1 2 3", "", model.POST_DEFAULT, 0, false)
+	require.NoError(t, err)
+
 	defer th.deleteUserPosts(th.User.Id)
 
 	params := &model.SearchParams{Terms: "\"channel test 1 2 3\""}