RemoveFromList() should remove all matches

RemoveFromList() should remove all matches.  Before this commit,
RemoveFromList() only removes the first match.  This commit rewrites
RemoveFromList() so that it will remove all matches.  Besides, a unit
test is written.

Note: aosp/461936 wants to make sure libc.so precedes libdl.so in
DT_NEEDED entries.  However, if there are two "libdl" in shared_libs,
aosp/461936 won't achieve its goal because RemoveFromList() (prior to
this commit) only removes the first "libdl".

Bug: 62815515
Test: Build sailfish and check libstagefright.so
Change-Id: I9bec563cbf800bff4bd508fb21e28869a92cfe56