[wpilibj] Clarify robot quit message (#3364)

Co-authored-by: David Vo <auscompgeek@users.noreply.github.com>

wpilibj/src/main/java/edu/wpi/first/wpilibj/RobotBase.java

@@ -300,7 +300,12 @@ public abstract class RobotBase implements AutoCloseable {
       DriverStation.reportError(
           "Unhandled exception instantiating robot " + robotName + " " + throwable.toString(),
           elements);
-      DriverStation.reportWarning("Robots should not quit, but yours did!", false);
+      DriverStation.reportWarning(
+          "The robot program quit unexpectedly."
+              + " This is usually due to a code error.\n"
+              + "  The above stacktrace can help determine where the error occurred.\n"
+              + "  See https://wpilib.org/stacktrace for more information.\n",
+          false);
       DriverStation.reportError("Could not instantiate robot " + robotName + "!", false);
       return;
     }
@@ -347,7 +352,12 @@ public abstract class RobotBase implements AutoCloseable {
       m_runMutex.unlock();
       if (!suppressExitWarning) {
         // startCompetition never returns unless exception occurs....
-        DriverStation.reportWarning("Robots should not quit, but yours did!", false);
+        DriverStation.reportWarning(
+            "The robot program quit unexpectedly."
+                + " This is usually due to a code error.\n"
+                + "  The above stacktrace can help determine where the error occurred.\n"
+                + "  See https://wpilib.org/stacktrace for more information.",
+            false);
         if (errorOnExit) {
           DriverStation.reportError(
               "The startCompetition() method (or methods called by it) should have "
@@ -361,7 +371,7 @@ public abstract class RobotBase implements AutoCloseable {
   }
 
   /**
-   * Suppress the "Robots should not quit" message.
+   * Suppress the "The robot program quit unexpectedly." message.
    *
    * @param value True if exit warning should be suppressed.
    */