common: fix license in some files

[ldorau]

This change is 

[sarahjelinek]

---

Reviewed 8 of 8 files at r1. Review status: all files reviewed at latest revision, all discussions resolved.

---

Comments from Reviewable

[ldorau]

Travis build failed:

tests/posix/CMakeFiles/gtest.dir/build.make:89: recipe for target 'tests/posix/gtest/src/gtest-stamp/gtest-download' failed
make[2]: *** [tests/posix/gtest/src/gtest-stamp/gtest-download] Error 1
CMakeFiles/Makefile2:1883: recipe for target 'tests/posix/CMakeFiles/gtest.dir/all' failed
make[1]: *** [tests/posix/CMakeFiles/gtest.dir/all] Error 2
Makefile:138: recipe for target 'all' failed
make: *** [all] Error 2

[krzycz]

---

Reviewed 8 of 8 files at r1. Review status: all files reviewed at latest revision, all discussions resolved, some commit checks failed.

---

Comments from Reviewable

[marcinslusarz]

I restarted the one failing job and it succeeded.