[hal,tests] Use waitForProgramStart in tests (#8429)

Change setProgramStarted to accept a boolean so it can be set back to
false by tests. This allows properly waiting for program start in tests.

wpilibj/src/main/java/org/wpilib/simulation/SimHooks.java

@@ -24,9 +24,13 @@ public final class SimHooks {
     SimulatorJNI.waitForProgramStart();
   }
 
-  /** Sets that the user program has started. */
-  public static void setProgramStarted() {
-    SimulatorJNI.setProgramStarted();
+  /**
+   * Sets flag that indicates if the user program has started.
+   *
+   * @param started true if started
+   */
+  public static void setProgramStarted(boolean started) {
+    SimulatorJNI.setProgramStarted(started);
   }
 
   /**