Merge "docs: Added v7 Palette library documentation and images to DAC training. https://android-dot-devsite.googleplex.com/training/material/palette-colors.html" into nyc-dev am: eae7f0b5 am: 4ef9c71a
am: f0e123c1

Change-Id: Idb85bd5963059b4e3d53bfef20c86f56f2d17cbc