Handle driver errors from remove, enroll and auth.

FingerprintService expects callbacks from the HAL to happen over
the provided notify() method.  However, there are some circumstances
when errors can't be propagated (i.e. the driver cannot be loaded).

In this case, the call to the method (remove(), enroll(), authenticate())
fails and we get a return status != 0. When this happens, FingerprintService
now sends an error response to the client. In general, this will mean
the driver is unavailable, so we send FINGERPRINT_ERROR_HW_UNAVAILABLE.

Fixes bug 23183484

Change-Id: Ifb40ba6fb1d960810043749fd8478ba37c968405
diff --git a/services/core/java/com/android/server/fingerprint/FingerprintService.java b/services/core/java/com/android/server/fingerprint/FingerprintService.java
index befa311..7807416 100644
--- a/services/core/java/com/android/server/fingerprint/FingerprintService.java
+++ b/services/core/java/com/android/server/fingerprint/FingerprintService.java
@@ -298,6 +298,7 @@
             final int result = daemon.enroll(cryptoToken, groupId, timeout);
             if (result != 0) {
                 Slog.w(TAG, "startEnroll failed, result=" + result);
+                dispatchError(mHalDeviceId, FingerprintManager.FINGERPRINT_ERROR_HW_UNAVAILABLE);
             }
         } catch (RemoteException e) {
             Slog.e(TAG, "startEnroll failed", e);
@@ -391,6 +392,7 @@
             final int result = daemon.authenticate(opId, groupId);
             if (result != 0) {
                 Slog.w(TAG, "startAuthentication failed, result=" + result);
+                dispatchError(mHalDeviceId, FingerprintManager.FINGERPRINT_ERROR_HW_UNAVAILABLE);
             }
         } catch (RemoteException e) {
             Slog.e(TAG, "startAuthentication failed", e);
@@ -433,12 +435,14 @@
             return;
         }
 
+        stopPendingOperations(true);
         mRemoveClient = new ClientMonitor(token, receiver, userId, restricted);
         // The fingerprint template ids will be removed when we get confirmation from the HAL
         try {
             final int result = daemon.remove(fingerId, userId);
             if (result != 0) {
                 Slog.w(TAG, "startRemove with id = " + fingerId + " failed, result=" + result);
+                dispatchError(mHalDeviceId, FingerprintManager.FINGERPRINT_ERROR_HW_UNAVAILABLE);
             }
         } catch (RemoteException e) {
             Slog.e(TAG, "startRemove failed", e);