feat(analytics): Set session sample rate for RUM (#3277)

Signed-off-by: James Rich <2199651+jamesarich@users.noreply.github.com>

core/analytics/src/google/kotlin/org/meshtastic/core/analytics/platform/GooglePlatformAnalytics.kt

@@ -140,6 +140,7 @@ constructor(
                 .trackLongTasks()
                 .trackNonFatalAnrs(true)
                 .trackUserInteractions()
+                .setSessionSampleRate(sampleRate)
                 .enableComposeActionTracking()
                 .build()
         Rum.enable(rumConfiguration)