For #15644: change apply to with in GleanMetricsService.

While the callback receiver is identical in these two methods, they're
semantically different: apply is for initializing the receiver while with
is anything else benefiting from a new `this` receiver.

I didn't change the usage of apply that has a return statement because I
was afraid my change might change behavior.

app/src/main/java/org/mozilla/fenix/components/metrics/GleanMetricsService.kt

@@ -762,7 +762,7 @@ class GleanMetricsService(
 
     internal fun setStartupMetrics() {
         setPreferenceMetrics()
-        Metrics.apply {
+        with(Metrics) {
             defaultBrowser.set(browsersCache.all(context).isDefaultBrowser)
             mozillaProductDetector.getMozillaBrowserDefault(context)?.also {
                 defaultMozBrowser.set(it)
@@ -819,7 +819,7 @@ class GleanMetricsService(
         // We purposefully make all of our preferences the string_list format to make data analysis
         // simpler. While it makes things like booleans a bit more complicated, it means all our
         // preferences can be analyzed with the same dashboard and compared.
-        Preferences.apply {
+        with(Preferences) {
             showSearchSuggestions.set(context.settings().shouldShowSearchSuggestions.toStringList())
             remoteDebugging.set(context.settings().isRemoteDebuggingEnabled.toStringList())
             telemetry.set(context.settings().isTelemetryEnabled.toStringList())