Allow dumpstate to read some directories.

This prevents denials while taking a bugreport.

Bug: 116711254
Test: cts-tradefed run cts -m CtsSecurityHostTestCases -t
android.security.cts.SELinuxHostTest#testNoBugreportDenials

Change-Id: I64f441eb66c355d03eaf7755f2e9d3e970305ecd