Drop external annotations support in build tools

External annotations will only be considered in the IDE for additional
inspections based on more precise types in Java libraries

compiler/testData/modules.xml/twoModules.xml

@@ -6,9 +6,6 @@
     <classpath path="bar"/>
     <classpath path="bar1"/>
     <classpath path="bar2"/>
-    <externalAnnotations path="baz"/>
-    <externalAnnotations path="baz1"/>
-    <externalAnnotations path="baz2"/>
   </module>
   <module name="name2" outputDir="out2" type="java-production">
     <sources path="2foo"/>
@@ -17,8 +14,5 @@
     <classpath path="2bar"/>
     <classpath path="2bar1"/>
     <classpath path="2bar2"/>
-    <externalAnnotations path="2baz"/>
-    <externalAnnotations path="2baz1"/>
-    <externalAnnotations path="2baz2"/>
   </module>
 </modules>