fix: fall back at once when a music app refuses the alarm

The start waited for PLAYING and nothing else, so an app that answered
the play request with an error (YouTube without Premium) left the alarm
vibrating in silence for the full 15 s START_TIMEOUT before the default
sound took over. An error stamped at or after the request, or a lost
connection, now ends the wait straight away. An error left over from
the user's own listening still doesn't count.

app/src/test/java/de/jeanlucmakiola/clockula/domain/ring/MediaRingPolicyTest.kt

@@ -29,6 +29,16 @@ class MediaRingPolicyTest {
         assertThat(MediaRingPolicy.shouldFallBack(long)).isTrue()
     }
 
+    @Test
+    fun `an error after the play request ends the start, an older one does not`() {
+        val requestedAt = 10_000L
+
+        assertThat(MediaRingPolicy.refusedStart(isError = true, updatedAtMillis = 10_050L, requestedAtMillis = requestedAt)).isTrue()
+        assertThat(MediaRingPolicy.refusedStart(isError = true, updatedAtMillis = requestedAt, requestedAtMillis = requestedAt)).isTrue()
+        assertThat(MediaRingPolicy.refusedStart(isError = true, updatedAtMillis = 9_000L, requestedAtMillis = requestedAt)).isFalse()
+        assertThat(MediaRingPolicy.refusedStart(isError = false, updatedAtMillis = 10_050L, requestedAtMillis = requestedAt)).isFalse()
+    }
+
     @Test
     fun `buffering forever is a failure too`() {
         val brief = run(*repeat(MediaPlayback.TRANSITIONING, MediaRingPolicy.BUFFER_GRACE - tick))