Replace strcpy with memcpy.

This fixes the warning
Call to function 'strcpy' is insecure as it does not provide bounding of
the memory buffer. As a side effect, it sliences the warning
frameworks/base/tools/aapt/Images.cpp:1270:50: warning: Potential leak
of memory pointed to by field 'data' [clang-analyzer-unix.Malloc]
frameworks/base/tools/aapt2/compile/Png.cpp:562:42: warning: Potential
leak of memory pointed to by field 'data' [clang-analyzer-unix.Malloc].

Bug: None
Test: The warning is gone.

Change-Id: I25f68ff85bea7069c21549c7deb7920d1877069e