com.android.tethering: set min_sdk_version 30

Tethering is updatable apex module that was launched in R, hence it and
all it dependencies should specify min_sdk_version <= 30.

Test: m
Bug: 171668006
Bug: 171330443
Change-Id: Ic91cf96dda6419d1038b0329b920f9cd24482aef
Merged-In: Ic91cf96dda6419d1038b0329b920f9cd24482aef
(cherry picked from commit bee20e84f87514b90c4b701b31582a7931c6e2ca)
(cherry picked from commit 1fe1e539e1d718ddc0a9a62b9a3d01ad22e7e699)
diff --git a/Tethering/common/TetheringLib/Android.bp b/Tethering/common/TetheringLib/Android.bp
index ddb6880..a10729d 100644
--- a/Tethering/common/TetheringLib/Android.bp
+++ b/Tethering/common/TetheringLib/Android.bp
@@ -29,6 +29,7 @@
     hostdex: true, // for hiddenapi check
     apex_available: ["com.android.tethering"],
     permitted_packages: ["android.net"],
+    min_sdk_version: "30",
 }
 
 filegroup {