Parse policy.rule_sets as a json array & fix stray metadata file creation in the bambi flow (#1233)

Author: khyatimahendru

services/src/main/java/com/google/bos/iot/core/bambi/Utils.java

@@ -17,7 +17,8 @@ public class Utils {
   public static final Set<String> LIST_TYPE_HEADERS = Set.of(
       "gateway.proxy_ids",
       "system.tags",
-      "tags"
+      "tags",
+      "policy.rule_sets"
   );
   public static final Set<Pattern> NON_NUMERIC_HEADERS_REGEX = Set.of(
       Pattern.compile("pointset\\.points\\..*\\.ref"),

services/src/main/java/com/google/bos/iot/core/bambi/model/BambiSiteModel.java

@@ -158,7 +158,7 @@ private void populateInDeviceMap(List<Map<String, String>> allDeviceData,
     if (allDeviceData != null) {
       for (Map<String, String> deviceData : allDeviceData) {
         String deviceId = deviceData.getOrDefault(DEVICE_ID, null);
-        if (deviceId != null) {
+        if (isNotEmpty(deviceId)) {
           deviceMap.putIfAbsent(deviceId, new LinkedHashMap<>());
           for (Entry<String, String> cell : deviceData.entrySet()) {
             deviceMap.get(deviceId)

services/src/test/java/com/google/bos/iot/core/bambi/BambiSiteModelTest.java

@@ -418,9 +418,8 @@ public void populateInDeviceMap_skipsRowsWithoutDeviceIdValueOrColumn() {
         headerOnlySheet("h"), headerOnlySheet("h"), headerOnlySheet("h"), headerOnlySheet("h"));
 
     Map<String, Map<String, String>> allMeta = model.getAllDevicesMetadata();
-    assertEquals(3, allMeta.size());
+    assertEquals(2, allMeta.size());
     assertNotNull(model.getDeviceMetadata("dev1"));
-    assertEquals("val_for_empty_id", model.getDeviceMetadata("").get(PREFIX_SYSTEM + ".data"));
     assertEquals("val_for_null_string_id",
         model.getDeviceMetadata("null_string").get(PREFIX_SYSTEM + ".data"));