Add capabilities to Zygote to fix valgrind.

Bug: 10455872
Change-Id: I98885e8cd1e4f9ab0d3e2af6d79b078a000db539

zygote.te

@@ -11,6 +11,9 @@ allow zygote self:capability setpcap;
 # Switch SELinux context to app domains.
 allow zygote system:process dyntransition;
 allow zygote appdomain:process dyntransition;
+# Allow zygote to read app data dirs (b/10455872)
+allow zygote appdomain:dir search;
+allow zygote appdomain:file { r_file_perms };
 # Move children into the peer process group.
 allow zygote system:process { getpgid setpgid };
 allow zygote appdomain:process { getpgid setpgid };