ref(session): Name the terminal-status check

`status != State.Ok` stated the mechanism while the comment carried the
meaning. An isTerminal helper says it directly and reads the same in
recordNonTerminatingUnhandledError, whose javadoc already spoke of terminal
states.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: buenaflor

sentry/src/main/java/io/sentry/Session.java

@@ -224,7 +224,7 @@ public boolean hasNonTerminatingUnhandledError() {
   @ApiStatus.Internal
   public boolean recordNonTerminatingUnhandledError() {
     try (final @NotNull ISentryLifecycleToken ignored = sessionLock.acquire()) {
-      if (status != State.Ok) {
+      if (isTerminal(status)) {
         return false;
       }
       hasNonTerminatingUnhandledError = true;
@@ -310,9 +310,9 @@ public boolean update(
       boolean sessionHasBeenUpdated = false;
       if (status != null) {
         this.status = status;
-        // the flag only decides how an Ok session is finalized, so an explicit terminal status
-        // such as a crash or an ANR takes precedence over a non-terminating error.
-        if (status != State.Ok) {
+        // the marker only decides how an Ok session is finalized, so a terminal status such as a
+        // crash or an ANR takes precedence over a non-terminating error.
+        if (isTerminal(status)) {
           hasNonTerminatingUnhandledError = false;
         }
         sessionHasBeenUpdated = true;
@@ -347,6 +347,11 @@ public boolean update(
     }
   }
 
+  /** A session can only leave {@link State#Ok}, every other status is final. */
+  private static boolean isTerminal(final @NotNull State state) {
+    return state != State.Ok;
+  }
+
   /**
    * Returns a logical clock.
    *