Move more arrays of strings to shareable memory

Move more arrays of strings to shareable memory (either .rodata or .data.rel.ro) to
potentially reduce RAM usage on Android. This is done by using char arrays instead
of pointers when possible or by marking the pointer as const when this is not
possible.

This also reduces the number of relocations (by getting rid of the pointers), which
makes loading the library faster.

BUG=249746

Review URL: https://codereview.chromium.org/49093004

git-svn-id: svn://svn.chromium.org/blink/trunk@160835 bbb929c8-8fbe-4397-9dbb-9b2b20218538