fix null pointer when storing platform sensors (opendcs#407)

platform sensors need to reference their platform

Author: adamkorynta

opendcs-rest-api/src/main/java/org/opendcs/odcsapi/res/PlatformResources.java

@@ -367,6 +367,7 @@ static Platform map(ApiPlatform platform) throws DatabaseException
 		ret.setPlatformDesignator(platform.getDesignator());
 		ret.lastModifyTime = new Date();
 		ret.platformSensors = platMap(platform.getPlatformSensors());
+		ret.platformSensors.forEach(p -> p.platform = ret);
 		if (platform.getConfigId() != null)
 		{
 			PlatformConfig config = new PlatformConfig();

opendcs-rest-api/src/test/java/org/opendcs/odcsapi/res/PlatformResourcesTest.java

@@ -39,6 +39,7 @@
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.when;
@@ -362,6 +363,7 @@ void testApiPlatformMap() throws Exception
 		assertMatch(plat.getPlatformSensors(), result.getPlatformSensors());
 		assertMatchMedium(plat.getTransportMedia(), result.getTransportMedia());
 		assertEquals(plat.getProperties(), result.getProperties());
+		result.platformSensors.forEach(s -> assertSame(result, s.platform));
 	}
 
 	private static void assertMatch(List<ApiPlatformSensor> apiPlatformSensors, Iterator<PlatformSensor> platformSensors)