Add debugging logs for scanner and scan enabler

Ignore-AOSP-First: nearby_not_in_aosp_yet
Test: built and read logs
Bug: 226983043
Change-Id: Ic2f5d0489ceee27ee351fbd94cababb6ba9d528f
diff --git a/nearby/service/java/com/android/server/nearby/fastpair/FastPairManager.java b/nearby/service/java/com/android/server/nearby/fastpair/FastPairManager.java
index 16c04de..a60a3a8 100644
--- a/nearby/service/java/com/android/server/nearby/fastpair/FastPairManager.java
+++ b/nearby/service/java/com/android/server/nearby/fastpair/FastPairManager.java
@@ -416,11 +416,13 @@
             return;
         }
         if (mScanEnabled) {
+            Log.v(TAG, "invalidateScan: scan is enabled");
             nearbyManager.startScan(new ScanRequest.Builder()
                             .setScanType(ScanRequest.SCAN_TYPE_FAST_PAIR).build(),
                     ForegroundThread.getExecutor(),
                     mScanCallback);
         } else {
+            Log.v(TAG, "invalidateScan: scan is disabled");
             nearbyManager.stopScan(mScanCallback);
         }
     }
diff --git a/nearby/service/java/com/android/server/nearby/provider/BleDiscoveryProvider.java b/nearby/service/java/com/android/server/nearby/provider/BleDiscoveryProvider.java
index db58476..4cb6d8d 100644
--- a/nearby/service/java/com/android/server/nearby/provider/BleDiscoveryProvider.java
+++ b/nearby/service/java/com/android/server/nearby/provider/BleDiscoveryProvider.java
@@ -144,6 +144,7 @@
                     + "because BluetoothLeScanner is null.");
             return;
         }
+        Log.v(TAG, "Ble scan stopped.");
         bluetoothLeScanner.stopScan(mScanCallback);
     }
 
diff --git a/nearby/service/java/com/android/server/nearby/provider/DiscoveryProviderManager.java b/nearby/service/java/com/android/server/nearby/provider/DiscoveryProviderManager.java
index af1c0b5..9003499 100644
--- a/nearby/service/java/com/android/server/nearby/provider/DiscoveryProviderManager.java
+++ b/nearby/service/java/com/android/server/nearby/provider/DiscoveryProviderManager.java
@@ -152,8 +152,11 @@
 
             ScanListenerRecord removedRecord =
                     mScanTypeScanListenerRecordMap.remove(listenerBinder);
+            Log.v(TAG, "DiscoveryProviderManager unregistered scan listener.");
             NearbyMetrics.logScanStopped(removedRecord.hashCode(), removedRecord.getScanRequest());
             if (mScanTypeScanListenerRecordMap.isEmpty()) {
+                Log.v(TAG, "DiscoveryProviderManager stops provider because there is no "
+                        + "scan listener registered.");
                 stopProviders();
                 return;
             }
@@ -162,6 +165,8 @@
 
             // Removes current highest scan mode requested and sets the next highest scan mode.
             if (removedRecord.getScanRequest().getScanMode() == mScanMode) {
+                Log.v(TAG, "DiscoveryProviderManager starts to find the new highest scan mode "
+                        + "because the highest scan mode listener was unregistered.");
                 @ScanRequest.ScanMode int highestScanModeRequested = ScanRequest.SCAN_MODE_NO_POWER;
                 // find the next highest scan mode;
                 for (ScanListenerRecord record : mScanTypeScanListenerRecordMap.values()) {