Remove explicit "mkdir -p" from Android postlink command

Ninja takes care of creating output directories already

BUG=

Review URL: https://codereview.chromium.org/1223273005

Cr-Original-Commit-Position: refs/heads/master@{#338421}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 6903b3b6502fa8d70d805fbb503ebc5dc182bbca

toolchain/android/BUILD.gn

@@ -64,20 +64,17 @@ template("android_gcc_toolchain") {
 
     android_strip = "${tool_prefix}strip"
 
-    mkdir_command = "mkdir -p lib.stripped"
     strip_command =
         "$android_strip --strip-unneeded -o $temp_stripped_soname $soname"
     replace_command = "if ! cmp -s $temp_stripped_soname $stripped_soname; then mv $temp_stripped_soname $stripped_soname; fi"
-    postsolink = "$mkdir_command && $strip_command && $replace_command"
+    postsolink = "$strip_command && $replace_command"
     solink_outputs = [ stripped_soname ]
 
     # We make the assumption that the gcc_toolchain will produce an exe with
     # the following definition.
     exe = "{{root_out_dir}}/{{target_output_name}}{{output_extension}}"
     stripped_exe = "exe.stripped/$exe"
-    mkdir_command = "mkdir -p exe.stripped"
+    postlink = "$android_strip --strip-unneeded -o $stripped_exe $exe"
-    strip_command = "$android_strip --strip-unneeded -o $stripped_exe $exe"
-    postlink = "$mkdir_command && $strip_command"
     link_outputs = [ stripped_exe ]
   }
 }