Drop BOARD_SEPOLICY_UNION.

As suggested in the comments on
https://android-review.googlesource.com/#/c/141560/
drop BOARD_SEPOLICY_UNION and simplify the build_policy logic.
Union all files found under BOARD_SEPOLICY_DIRS.

Change-Id: I4214893c999c23631f5456cb1b8edd59771ef13b
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
diff --git a/target/board/generic/BoardConfig.mk b/target/board/generic/BoardConfig.mk
index e06c985..393492b 100644
--- a/target/board/generic/BoardConfig.mk
+++ b/target/board/generic/BoardConfig.mk
@@ -76,22 +76,6 @@
 TARGET_USERIMAGES_SPARSE_EXT_DISABLED := true
 
 BOARD_SEPOLICY_DIRS += build/target/board/generic/sepolicy
-BOARD_SEPOLICY_UNION += \
-        bootanim.te \
-        device.te \
-        domain.te \
-        file.te \
-        file_contexts \
-        goldfish_setup.te \
-        goldfish_logcat.te \
-        property.te \
-        property_contexts \
-        qemu_props.te \
-        qemud.te \
-        rild.te \
-        shell.te \
-        surfaceflinger.te \
-        system_server.te
 
 ifeq ($(TARGET_PRODUCT),sdk)
   # include an expanded selection of fonts for the SDK.
diff --git a/target/board/generic_mips/BoardConfig.mk b/target/board/generic_mips/BoardConfig.mk
index b40f9ba..13d1c9f 100644
--- a/target/board/generic_mips/BoardConfig.mk
+++ b/target/board/generic_mips/BoardConfig.mk
@@ -61,19 +61,3 @@
 TARGET_USERIMAGES_SPARSE_EXT_DISABLED := true
 
 BOARD_SEPOLICY_DIRS += build/target/board/generic/sepolicy
-BOARD_SEPOLICY_UNION += \
-        bootanim.te \
-        device.te \
-        domain.te \
-        file.te \
-        file_contexts \
-        goldfish_setup.te \
-        goldfish_logcat.te \
-        property.te \
-        property_contexts \
-        qemu_props.te \
-        qemud.te \
-        rild.te \
-        shell.te \
-        surfaceflinger.te \
-        system_server.te
diff --git a/target/board/generic_x86/BoardConfig.mk b/target/board/generic_x86/BoardConfig.mk
index 78b7590..d5f0531 100644
--- a/target/board/generic_x86/BoardConfig.mk
+++ b/target/board/generic_x86/BoardConfig.mk
@@ -45,21 +45,3 @@
 BOARD_SEPOLICY_DIRS += \
         build/target/board/generic/sepolicy \
         build/target/board/generic_x86/sepolicy
-
-BOARD_SEPOLICY_UNION += \
-        device.te \
-        domain.te \
-        file.te \
-        file_contexts \
-        healthd.te \
-        installd.te \
-        goldfish_setup.te \
-        goldfish_logcat.te \
-        property.te \
-        property_contexts \
-        qemu_props.te \
-        qemud.te \
-        rild.te \
-        shell.te \
-        system_server.te \
-        zygote.te