CameraITS: fix fixed focus lens check

It is possible minimum focus distance is not reported on some
devices supporting AF.

Bug: 19669696
Change-Id: I447cea7b1876f3cc06eca43718cfd0e4aae643ae
diff --git a/apps/CtsVerifier/src/com/android/cts/verifier/camera/its/ItsService.java b/apps/CtsVerifier/src/com/android/cts/verifier/camera/its/ItsService.java
index a305cd2..c01fd79 100644
--- a/apps/CtsVerifier/src/com/android/cts/verifier/camera/its/ItsService.java
+++ b/apps/CtsVerifier/src/com/android/cts/verifier/camera/its/ItsService.java
@@ -822,8 +822,10 @@
                     doAF = triggers.getBoolean(TRIGGER_AF_KEY);
                 }
             }
-            if (doAF && mCameraCharacteristics.get(
-                            CameraCharacteristics.LENS_INFO_MINIMUM_FOCUS_DISTANCE) == 0) {
+            Float minFocusDistance = mCameraCharacteristics.get(
+                    CameraCharacteristics.LENS_INFO_MINIMUM_FOCUS_DISTANCE);
+            boolean isFixedFocusLens = minFocusDistance != null && minFocusDistance == 0.0;
+            if (doAF && !isFixedFocusLens) {
                 // Send a dummy result back for the code that is waiting for this message to see
                 // that AF has converged.
                 Logt.i(TAG, "Ignoring request for AF on fixed-focus camera");