GLES2Dbg: use dump.gles2dbg file when fails to create socket

setprop debug.egl.debug_forceUseFile 1: always use file
setprop debug.egl.debug_maxFileSize <int MB>: exit when reached
setprop debug.egl.debug_filePath <path>: may need to make the file
 writable first.
setprop debug.egl.debug_port <unsigned short>
setprop debug.egl.debug_proc <proc cmdline>: to match debuggee process

Change-Id: I34ca1f3092f3abf17e2ded9d1689d0cdef6e07e8
Signed-off-by: David Li <davidxli@google.com>