Split MOUNT_FLAG_VISIBLE into MOUNT_FLAG_VISIBLE_FOR_{READ, WRITE}

IVold.MOUNT_FLAG_VISIBLE is split into MOUNT_FLAG_VISIBLE_FOR_READ and
MOUNT_FLAG_VISIBLE_FOR_WRITE.
Accordingly, VolumeBase::MountFlags::kVisible is split into
kVisibleForRead and kVisibleForWrite.

Bug: 206019156
Test: m
Change-Id: Ia55673400d9f713f221650e1335a46ba11f6f027
Merged-In: Ia55673400d9f713f221650e1335a46ba11f6f027
diff --git a/model/EmulatedVolume.cpp b/model/EmulatedVolume.cpp
index 6f21ff8..b686437 100644
--- a/model/EmulatedVolume.cpp
+++ b/model/EmulatedVolume.cpp
@@ -246,7 +246,7 @@
 
 status_t EmulatedVolume::doMount() {
     std::string label = getLabel();
-    bool isVisible = getMountFlags() & MountFlags::kVisible;
+    bool isVisible = isVisibleForWrite();
 
     mSdcardFsDefault = StringPrintf("/mnt/runtime/default/%s", label.c_str());
     mSdcardFsRead = StringPrintf("/mnt/runtime/read/%s", label.c_str());