Moved Cronet code under Connectivity

$ cp -r Cronet/ Connectivity/
$ rm -r Cronet/*

Bug: 251054736
Test: atest CronetApiTest
Change-Id: I25d5238fe530ffaa830ce64c67b351d40b8030ea
CTS-Coverage-Bug: 251012627
diff --git a/Cronet/prebuilt/VERSION b/Cronet/prebuilt/VERSION
new file mode 100644
index 0000000..c16ab94
--- /dev/null
+++ b/Cronet/prebuilt/VERSION
@@ -0,0 +1,4 @@
+MAJOR=80
+MINOR=0
+BUILD=3986
+PATCH=0