In the #48216 Material deps were updated to v15,
but the components and modules in DevTools were not
updated to MDC nor replaced with the legacy definitions.
PR Close#48420
This commit runs tslint --fix with the angular/angular tslint configuration on the files inside the devtools codebase.
Notably, the file-header rule in `tslint.json` was missing a default attribute. This commit adds that default attribute and sets it to the
license header that is present in all files in this repo. After running tslint --fix with this default added, this commit added the license header to all files in the devtools directory. Note for the reviewer: the automatically added license headers were added as comments with the "/*!" prefix. Since we want these comments removed in builds, and the rest of the codebase uses "/**", a simple find and replace was performed on the devtools directory to change these prefixes to "/**".
Formats the entire devtools directory with the ng-dev formatting tool. Previously we relied on prettier, so this commit also remove prettier from devtools' dependencies.
