Make libicuuc shared library only

VTS no longer needs the static libicuuc.

Effectively, it reverts "Provide static libicuuc for tests"

This reverts commit 9adf475a99509560cc102d7efc559a2d808504b6

Bug: 121468463
Test: m vts
Change-Id: I12328ae220cd61b2ff3dc0fa0def304fdf428119
diff --git a/icu4c/source/common/Android.bp b/icu4c/source/common/Android.bp
index 34362d4..e192b99 100644
--- a/icu4c/source/common/Android.bp
+++ b/icu4c/source/common/Android.bp
@@ -74,7 +74,7 @@
 //
 // Build for the host and target.
 //
-cc_library {
+cc_library_shared {
     name: "libicuuc",
     host_supported: true,
     unique_host_soname: true,