/lib/udev/rules.d/10-hide-android-partitions-nexus7.rules is in ubuntu-defaults-nexus7 0.54.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | KERNEL=="mmcblk0p3", ENV{UDISKS_IGNORE}="1"
KERNEL=="mmcblk0p4", ENV{UDISKS_IGNORE}="1"
KERNEL=="mmcblk0p7", ENV{UDISKS_IGNORE}="1"
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