Underscore character may cause bpf prog/map naming collision. For
example, x.o with map y_z and x_y.o with map z both result in x_y_z
prog/map name, which should be prevented during compile-time.
aosp/2147825 will prohibit underscore character in bpf source name
(source name derives the obj name). Existing bpf modules with underscore
characters in source name need to be updated accordingly.
Bug: 236706995
Test: atest bpf_existence_test
Test: adb root; adb shell ls -l sys/fs/bpf/net_shared | grep dscpPolicy
Change-Id: Ibe98944d09d42bd11b78b5e9ae35ded48c70416d
74ff3ee501