Use mount modes logic from StorageManagerService

This leads to less code maintenance for Android S+. This also keeps both
of them from diverging for primary and secondary volumes using best code
practices.

Bug: 175796984
Bug: 173505864
Test: atest DownloadProviderTest
Test: atest CtsScopedStorageHostTest
Test: atest android.scopedstorage.cts.host.PublicVolumeHostTest#testCheckInstallerAppAccessToObbDirs
Test: atest android.scopedstorage.cts.host.PublicVolumeHostTest#testCheckInstallerAppCannotAccessDataDirs
Test: atest android.scopedstorage.cts.host.PublicVolumeHostTest#testCantAccessOtherAppsExternalDirs
Change-Id: Ieee5824fac44174747fdc5b41582ba3ceb77e9c6
1 file changed