CI: use local registry, part 2 of 3: fix tests

This commit gets tests working under the new local-registry system:

  * amend a few image names, mostly just sticking to a consistent
    list of those images in our registry cache. Mostly minor
    tag updates.

  * trickier: pull_test: change some error messages, and remove
    a test that's now a NOP. Basically, with a local (unprotected)
    registry we always get "404 manifest unknown"; with a real
    registry we'll get "403 I can't tell you".

  * trickiest: seccomp_test: build our own images at run time,
    with our desired labels. Until now we've been pulling
    prebuilt images, but those will not copy to the local
    cache registry. Something about v1? Anyhow, I gave up
    trying to cache them, and the workaround is straightforward.

Also took the liberty of strengthening a few error-message checks

Signed-off-by: Ed Santiago <santiago@redhat.com>

test/e2e/info_test.go

@@ -117,13 +117,11 @@ var _ = Describe("Podman Info", func() {
 			Expect(session.OutputToString()).To(Equal("false"))
 		}
 
-		session = podmanTest.Podman([]string{"info", "--format", "{{.Host.RemoteSocket.Exists}}"})
-		session.WaitWithDefaultTimeout()
-		Expect(session).Should(ExitCleanly())
 		if IsRemote() {
-			Expect(session.OutputToString()).To(ContainSubstring("true"))
-		} else {
-			Expect(session.OutputToString()).To(ContainSubstring("false"))
+			session = podmanTest.Podman([]string{"info", "--format", "{{.Host.RemoteSocket.Exists}}"})
+			session.WaitWithDefaultTimeout()
+			Expect(session).Should(ExitCleanly())
+			Expect(session.OutputToString()).To(Equal("true"))
 		}
 
 	})