Update getCheckedItemPositions() documentation

getCheckedItemPositions()'s documentation previously mentioned the 
returned SparseBooleanArray was only containing checked item positions 
(i.e. get(int position) always returning true). In practice, this is 
wrong, because getCheckedItemPositions() returns mCheckStates which 
basically contains all key-value mappings that have been used. As a 
consequence if the item at position p is checked and unchecked, the 
returned SparseBooleanArray will contain a (p, false) mapping.

Another option could be to delete all keys having a false value.

Change-Id: I15f8fc2a1ba3f1501af126c272b827402cfd8b14
MediaFormat: Explain that KEY_COLOR_FORMAT is used with decoders as well

If reading the decoded pixel data (instead of letting the system
render it), this is critical for interpreting the data correctly.

The video MediaCodec CTS tests use this MediaFormat key in this
way as well.

Therefore, make sure the documentation reflects the actual use of
this field - claiming that it is encoder-only is misleading.

Change-Id: I9bfd295a95dd3e7d1fa3189886fd243b07bb82cc
464xlat: use a gatewayed route, not point-to-point

Various applications such as Skype and our legacy VPN code
do not understand routes pointed directly at point-to-point
interfaces and require a default gateway IPv4 address in
order to function.

Grudgingly accept that routes without default gateways Are Hard
and use gatewayed routes instead. This causes routing to go from:

default dev clat4  scope link

to:

default via 192.0.0.4 dev clat4  scope link
192.0.0.4 dev clat4  scope link

and those apps now work.

Bug: 9597256
Bug: 9597516
Change-Id: I7b7890873802d3cb99affd6eb70b8ab75e7a2cf6
Make legacy VPN work over stacked interfaces.

On stacked interfaces like 464xlat, Legacy VPN can't find the
default gateway because it uses getRoutes, which only returns
routes for the base link and not for the stacked links. It also
assumes that the interface that the default route points to is
the interface for the base link (e.g., rmnet0) instead of the
interface the route actually points to (e.g., clat4).

Fix this by calling getAllRoutes to find the default IPv4 route,
and get the interface name from the route we find instead of
assuming it's the base interface.

Bug: 9597516
Change-Id: Ia6ce0b6258a421cd22f60dedca7e94176b32176b
Merge "Update getCheckedItemPositions() documentation"
Merge "464xlat: use a gatewayed route, not point-to-point"
Merge "Make legacy VPN work over stacked interfaces."
Merge "MediaFormat: Explain that KEY_COLOR_FORMAT is used with decoders as well"