Support7Demos: Set LOCAL_MIN_SDK_VERSION to 7

Bug: 28302992
Change-Id: I549401fb9ea225afa081d229a2392f952bd11f7b
diff --git a/samples/Support7Demos/Android.mk b/samples/Support7Demos/Android.mk
index 0cf9dcb..9a3368d 100644
--- a/samples/Support7Demos/Android.mk
+++ b/samples/Support7Demos/Android.mk
@@ -20,6 +20,7 @@
 LOCAL_PACKAGE_NAME := Support7Demos
 LOCAL_MODULE_TAGS := samples tests
 LOCAL_SDK_VERSION := current
+LOCAL_MIN_SDK_VERSION := 7
 LOCAL_SRC_FILES := $(call all-java-files-under, src)
 LOCAL_STATIC_ANDROID_LIBRARIES := \
     android-support-v7-appcompat \