Since radioext has already moved to this folder, it doesn't make sense
for the base folder to be dump_modemlog. This change moves it to its
own subfolder so that we can also add more in the future.
Test: build and flash, trigger bugreport and check modem logs are there
Bug: 302435001
Change-Id: Ia83378074068526023f591d63b1e5ac4700b8103
Bug: 240530709
Test: adb bugreport
and the following file got to dumpstate_board.bin:
extended_log_uim.txt
extended_log_os.txt
nv_normal.bin
nv_protected.bin
Change-Id: Ie6439c7487b11c564cd6c0d1266928e6b9b384ee
