Set min_sdk_version for java imports in pom2bp

Previously min_sdk_version was only set for *_library build rules, and
not for *_import targets. This made min_sdk_version default to
sdk_version, which is usually "current", which is not correct for these
libraries.

Test: pom2bp -default-min_sdk_version 24 for androidx
Change-Id: I3b029315abeb559e66efad847ae664efb79f4509
diff --git a/cmd/pom2bp/pom2bp.go b/cmd/pom2bp/pom2bp.go
index d9116b0..d31489e 100644
--- a/cmd/pom2bp/pom2bp.go
+++ b/cmd/pom2bp/pom2bp.go
@@ -401,6 +401,8 @@
         {{- end}}
     ],
     {{- end}}
+    {{- else if not .IsHostOnly}}
+    min_sdk_version: "{{.DefaultMinSdkVersion}}",
     {{- end}}
 }
 `))
@@ -442,6 +444,8 @@
         {{- end}}
     ],
     {{- end}}
+    {{- else if not .IsHostOnly}}
+    min_sdk_version: "{{.DefaultMinSdkVersion}}",
     {{- end}}
 }