Generate a single NOTICE file rather than one per library. All the
headers come from libc these days anyway.
Test: tools/update_notice.sh
Bug: None
Change-Id: I127da185fdabc2815042e19aea74c507ec108f46
Also updates the license files, since apparently they're out of date.
Test: repo upload --cbr .
Bug: None
Change-Id: Ic8d855a7ee5185c4933da699292868e02ef79531