[sim] Add Java wrapper for getProgramStarted (#2566)

Also move SimHooks to wpilibj (to match wpilibc).

hal/src/main/java/edu/wpi/first/hal/simulation/SimulatorJNI.java

@@ -13,6 +13,7 @@ public class SimulatorJNI extends JNIWrapper {
   public static native void setRuntimeType(int type);
   public static native void waitForProgramStart();
   public static native void setProgramStarted();
+  public static native boolean getProgramStarted();
   public static native void restartTiming();
   public static native void pauseTiming();
   public static native void resumeTiming();

hal/src/main/native/sim/jni/SimulatorJNI.cpp

@@ -146,6 +146,18 @@ Java_edu_wpi_first_hal_simulation_SimulatorJNI_setProgramStarted
   HALSIM_SetProgramStarted();
 }
 
+/*
+ * Class:     edu_wpi_first_hal_simulation_SimulatorJNI
+ * Method:    getProgramStarted
+ * Signature: ()Z
+ */
+JNIEXPORT jboolean JNICALL
+Java_edu_wpi_first_hal_simulation_SimulatorJNI_getProgramStarted
+  (JNIEnv*, jclass)
+{
+  return HALSIM_GetProgramStarted();
+}
+
 /*
  * Class:     edu_wpi_first_hal_simulation_SimulatorJNI
  * Method:    restartTiming

wpilibj/src/main/java/edu/wpi/first/wpilibj/simulation/SimHooks.java

@@ -5,7 +5,9 @@
 /* the project.                                                               */
 /*----------------------------------------------------------------------------*/
 
-package edu.wpi.first.hal.simulation;
+package edu.wpi.first.wpilibj.simulation;
+
+import edu.wpi.first.hal.simulation.SimulatorJNI;
 
 public final class SimHooks {
   private SimHooks() {
@@ -23,6 +25,10 @@ public final class SimHooks {
     SimulatorJNI.setProgramStarted();
   }
 
+  public static boolean getProgramStarted() {
+    return SimulatorJNI.getProgramStarted();
+  }
+
   public static void restartTiming() {
     SimulatorJNI.restartTiming();
   }