Prepare SDK for KLP MR1. Do not merge.

System images are in 19 rev 2 for MR1 (since they have minor.major)

platform-tools: update the API diff file that lint uses (not automated yet.)
build-tools: llvm-rs-cc issue affecting RS NDK mode in Gradle.

Note that support is set to 19.0.1 which means it will have to be
released using the new addon.xsd format that allows extras to have a
major.micro.minor format. That will be an interesting way to test this
feature.

Change-Id: Id755770f8a121edffa36e0fcb70488c452087440
Update api-versions.xml for latest API changes

Change-Id: Id979db34a83da704df38c1250fb946baf928650b
Updating sdk.atree to reflect new set of samples

Change-Id: I1308d65f77783fc7f43fdc36bf90a59a137ec73f
SDK Repository: switch to sdk addon revision 6.

addon-6.xsd changes <extra><revision> from an int (major only)
to a full <revision> element with major.micro.minor (but not
preview part.)

(cherry picked from commit 7657a590830cfe87fb2dc6ff03c0dcb7589c0bdf)

Change-Id: Iedff23a757dd3fd8d9e8006a2aec072ce2c71e8d
Adjust SDK revisions for KLP MR1 for platform and samples

Platform changes from 19 r1 to 19 r2.
Samples  changes from 19 r1 to 19 r2.

Change-Id: Ia391fef04468211f460f3e8d6ab83e0a4dc12a70
Add API demo for game style system UI interaction.

Shows the ideal way for a game to interact with system UI, hiding
the status bar and nav bar while being played, making them visible
when paused or otherwise interacting with controls of the game,
and determing layout of game controls to not be covered by the
status bar or nav bar.

Change-Id: Ia192c31321113d81f96c06c7a69a06ef72c4682a
docs: Code sample for game controller training class.

Change-Id: I14f7046c7fba4f67838513af2ca2abbca4c3561a
Properly package the RS support bc file.

Change-Id: Ia55b597085c97cb07029b812392a618a4670ff36
Update build tools to 19.0.2

Change-Id: I339c292aece1101a6afaf89db20a9d985427e561
Bundle Noto fonts with the SDK

Change-Id: I28c48b3b5dbd761ef0391497e834f315ac83cae4
incremented Pkg.Revision

Change-Id: Idb5497398525887a1f05dac421b0bd83de046a89
Updated sdk.atree to include new samples for feb sample launch

Change-Id: I71af239a0bf0f146345e243720d9e4300c5ed1f6