Add truth Subjects for ToolchainContext and ToolchainCollection.

PiperOrigin-RevId: 314418679
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/ToolchainCollection.java b/src/main/java/com/google/devtools/build/lib/analysis/ToolchainCollection.java
index 4991889..41c98f4 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/ToolchainCollection.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/ToolchainCollection.java
@@ -40,11 +40,11 @@
   /** A map of execution group names to toolchain contexts. */
   public abstract ImmutableMap<String, T> getContextMap();
 
-  T getDefaultToolchainContext() {
+  public T getDefaultToolchainContext() {
     return getContextMap().get(DEFAULT_EXEC_GROUP_NAME);
   }
 
-  boolean hasToolchainContext(String execGroup) {
+  public boolean hasToolchainContext(String execGroup) {
     return getContextMap().containsKey(execGroup);
   }
 
@@ -58,7 +58,7 @@
         .collect(toImmutableSet());
   }
 
-  ImmutableSet<String> getExecGroups() {
+  public ImmutableSet<String> getExecGroups() {
     return getContextMap().keySet();
   }