When suid_dumpable == 2, set dumpable to 0 for apps

Core dumps for zygote children are expected to be disabled in CTS, but
on system like Chrome OS, suid_dumpable is 2, thus not compliant with
CTS.  This patch sets dumpable to 0 for apps when suid_dumpable is 2.

Test: atest \
      android.permission.cts.FileSystemPermissionTest#testAllBlockDevicesAreSecure \
      android.os.cts.SecurityFeaturesTest#testPrctlDumpable \
      android.seccomp.cts.SeccompHostJUnit4DeviceTest#testCTSSyscallBlocked
Bug: 62379607
Bug: 79094505

Change-Id: Ida43b16590dca1e85a0f9549c779e38c00bc6a0c