[fuchsia] Report all unexpected MetricsRecorder disconnections.

The fuchsia.legacymetrics.MetricsRecorder channel is expected to remain
connected until the service explicitly signals OnCloseSoon, or the
fuchsia.web.Context is destroyed, so log unexpected disconnections
regardless of the reported disconnect status.

Bug: b/158283552
Change-Id: I3bdf2f935c3ce2db04d0d8812b50703822703fbf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2232367
Auto-Submit: Wez <wez@chromium.org>
Commit-Queue: Kevin Marshall <kmarshall@chromium.org>
Reviewed-by: Kevin Marshall <kmarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#777427}

fuchsia/base/legacymetrics_client.cc

@@ -147,8 +147,7 @@ void LegacyMetricsClient::DrainBuffer() {
 }
 
 void LegacyMetricsClient::OnMetricsRecorderDisconnected(zx_status_t status) {
-  ZX_LOG_IF(ERROR, status != ZX_ERR_PEER_CLOSED, status)
-      << "MetricsRecorder connection lost.";
+  ZX_LOG(ERROR, status) << "MetricsRecorder connection lost.";
 
   // Stop recording & reporting user events.
   user_events_recorder_.reset();