fix dollar sign in public file

[realityJie]

I try to remove some item with dollar sign in public.xml file.
If we use aapt2 command to create R.java file, it will cause some error:

/home/jerry/git_code/AgentPack/temp/9dc1d1ce-9f15-11ea-95ce-e0d55ebafe0d/res/values/public.xml:983: error: resource 'drawable/$avd_hide_password__0' has invalid entry name '$avd_hide_password__0'. Invalid character '$avd_hide_password__0'.
/home/jerry/git_code/AgentPack/temp/9dc1d1ce-9f15-11ea-95ce-e0d55ebafe0d/res/values/public.xml:984: error: resource 'drawable/$avd_hide_password__1' has invalid entry name '$avd_hide_password__1'. Invalid character '$avd_hide_password__1'.
/home/jerry/git_code/AgentPack/temp/9dc1d1ce-9f15-11ea-95ce-e0d55ebafe0d/res/values/public.xml:985: error: resource 'drawable/$avd_hide_password__2' has invalid entry name '$avd_hide_password__2'. Invalid character '$avd_hide_password__2'.
/home/jerry/git_code/AgentPack/temp/9dc1d1ce-9f15-11ea-95ce-e0d55ebafe0d/res/values/public.xml:986: error: resource 'drawable/$avd_show_password__0' has invalid entry name '$avd_show_password__0'. Invalid character '$avd_show_password__0'.
/home/jerry/git_code/AgentPack/temp/9dc1d1ce-9f15-11ea-95ce-e0d55ebafe0d/res/values/public.xml:987: error: resource 'drawable/$avd_show_password__1' has invalid entry name '$avd_show_password__1'. Invalid character '$avd_show_password__1'.
/home/jerry/git_code/AgentPack/temp/9dc1d1ce-9f15-11ea-95ce-e0d55ebafe0d/res/values/public.xml:988: error: resource 'drawable/$avd_show_password__2' has invalid entry name '$avd_show_password__2'. Invalid character '$avd_show_password__2'.

on the other hand to fix #1776

[iBotPeaches]

Hey, I don't think this is the right path. We can't just remove characters. The correct fix is allowing a more restrictive aapt/aapt2 to not care about these chars as they were allowed in older builds.

Thanks for the PR, but I'm going to close this route.