[ApiModel] Enable api modeling

This CL enables api-modeling for all references to ensure no inlining of
methods into other methods with a lower api level. The CL also ensure
that merged classes will have the same api level.

RELNOTES: R8 prevents soft-verification errors by modeling all references to android api's introduced later than min-api. Concretely, R8 disables inlining of methods with a higher api-level into methods with a lower level and merging of classes with different levels.

Bug: 138781768
Bug: 187496508
Fixes: 188388130
Fixes: 204063897
Change-Id: I3e0008384d719eaaf09cde0b12702ec9bed658d3
diff --git a/tools/chrome_data.py b/tools/chrome_data.py
index 0d4329d..ebae542 100644
--- a/tools/chrome_data.py
+++ b/tools/chrome_data.py
@@ -248,6 +248,7 @@
         'inputs': [os.path.join(V180917_BASE, path) for path in INPUT_JARS],
         'pgconf': [os.path.join(V180917_BASE, path) for path in PG_CONFS],
         'libraries': [os.path.join(V180917_BASE, path) for path in LIBRARIES],
+        'min-api': '21',
     },
   },
   '200430': {