Linux kernel included a commit 17efe505a4c3df88d3e13051f421d27d7178d47f
that creates .incomplete folder on mounting incfs. However .incomplete
folder is only accessible for root with 0700 permission. So system_server
has no permission to access it.
By creating .incomplete folder with 0777 permission in system_server,
incfs won't have to create incomplete folder implicitly.
Bug: 176400491
Test: CtsIncrementalInstallHostTestCases
CtsContentTestCases android.content.pm.cts.PackageManagerShellCommandIncrementalTest
CtsStatsdHostTestCases android.cts.statsd.atom.UidAtomTests#testPackageInstallerV2MetricsReported
GtsIncrementalInstallProxyHostTestCases
Change-Id: Icb7babe3b482a089019f981fe149de7d619ce87e
6aa40c395f