Switch to mksh as the default shell.

Switch the emulator builds to ash to make sure it still
works, in case we find that we need to go back to using ash.

Change-Id: Id5641940b63cc4225011be1c375f4c86ec4d21cc
diff --git a/core/config.mk b/core/config.mk
index 20a2582..3240e94 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -105,8 +105,8 @@
 # TODO: do symbol compression
 TARGET_COMPRESS_MODULE_SYMBOLS := false
 
-# Default shell is ash. Other possible value is mksh.
-TARGET_SHELL := ash
+# Default shell is mksh. Other possible value is ash.
+TARGET_SHELL := mksh
 
 # ###############################################################
 # Include sub-configuration files
diff --git a/target/board/generic/BoardConfig.mk b/target/board/generic/BoardConfig.mk
index 26bf6ab..2b05f79 100644
--- a/target/board/generic/BoardConfig.mk
+++ b/target/board/generic/BoardConfig.mk
@@ -13,5 +13,5 @@
 # no hardware camera
 USE_CAMERA_STUB := true
 
-# Set /system/bin/sh to mksh, not ash, to test the transition.
-TARGET_SHELL := mksh
+# Set /system/bin/sh to ash, not mksh, to make sure we can switch back.
+TARGET_SHELL := ash
diff --git a/target/board/generic_x86/BoardConfig.mk b/target/board/generic_x86/BoardConfig.mk
index 75fc040..7277908 100644
--- a/target/board/generic_x86/BoardConfig.mk
+++ b/target/board/generic_x86/BoardConfig.mk
@@ -18,5 +18,5 @@
 # no hardware camera
 USE_CAMERA_STUB := true
 
-# Set /system/bin/sh to mksh, not ash, to test the transition.
-TARGET_SHELL := mksh
+# Set /system/bin/sh to ash, not mksh, to make sure we can switch back.
+TARGET_SHELL := ash