bump min_sdk_version from 29 (Q) to 30 (R)

Mainline no longer supports Q.
These files were recently moved into p/m/C as part of a refactor.

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I0f06ace921db6c79d63c0048bdb73d167ff606cf
diff --git a/staticlibs/client-libs/Android.bp b/staticlibs/client-libs/Android.bp
index c560045..c938dd6 100644
--- a/staticlibs/client-libs/Android.bp
+++ b/staticlibs/client-libs/Android.bp
@@ -6,7 +6,7 @@
     name: "netd-client",
     srcs: ["netd/**/*"],
     sdk_version: "system_current",
-    min_sdk_version: "29",
+    min_sdk_version: "30",
     apex_available: [
         "//apex_available:platform",
         "com.android.tethering",