Reduce minimum SDK version to 26

server/build.gradle.kts

@@ -137,7 +137,7 @@ android {
 		applicationId = "dev.slimevr.server"
 
 		// Defines the minimum API level required to run the app.
-		minSdk = 33
+		minSdk = 26
 
 		// Specifies the API level used to test the app.
 		targetSdk = 33

server/src/main/java/dev/slimevr/protocol/pubsub/PubSubHandler.java

@@ -73,7 +73,7 @@ public class PubSubHandler extends ProtocolHandler<PubSubHeader> {
 			.stream()
 			.filter((handle) -> handle == finalSubHandle)
 			.findFirst();
-		if (first.isEmpty()) {
+		if (!first.isPresent()) {
 			conn.getContext().getSubscribedTopics().add(finalSubHandle);
 		}
 

server/src/main/java/dev/slimevr/tracking/processor/skeleton/HumanSkeleton.java

@@ -192,7 +192,12 @@ public class HumanSkeleton {
 	) {
 		this(humanPoseManager);
 
-		setTrackersFromList(Objects.requireNonNullElseGet(trackers, () -> new FastList<>(0)));
+		List<? extends Tracker> trackersList = trackers;
+		if (trackersList == null) {
+			trackersList = new FastList<>(0);
+		}
+
+		setTrackersFromList(trackersList);
 	}
 	// #endregion