am a5273888: am 538abc5b: am d6aeae14: Merge "Don\'t serialize required fields whose \'has\' flags are unset."

* commit 'a5273888480392ff8a8b0ea3af6617e18dbb1ed2':

* commit '81d0f437ba2bb34cd59a019c2f15f862a9c5d45b':

* commit '55c3d6d9fa8287676c6502ad20199bd932730681':

am 7c0eadd4: am 6a6b3b38: am cea499ac: Merge "Nano: don\'t generate accessor methods for nested methods"

* commit '7c0eadd45cb4e0fef8afffe1626c2e4711418b49':

am da929e3e: am 98c9208a: am b6089cca: Merge commit \'0afd5a4d782037ea641d75d595cf5d38ed6978ac\' into HEAD

* commit 'da929e3ea6310e7dc46745f191200afc489600e6':

am 6597e4f2: am 485b7645: am c4c4a562: Merge commit \'7cb6b37f3799affce9e1be39977d4419283df795\' into HEAD

* commit '6597e4f210be48b731e995c6c9950046ccf7689b':

am b3ad7eae: am 0143d32d: am f5271c9c: Merge "Align with main: two ways of parsing repeated packable fields."

* commit 'b3ad7eaeb3233d9842a74e2252efa189d4c0524a':

am 4115d56f: am 0afd5a4d: am 3e0d99fa: Merge "Update MessageNano#toString() to return mostly valid TextFormat."

* commit '4115d56f3d03ca788a08a0a1eb6c79fa107550d3':

* commit '139bd6ac80ca61f85796bded692eeb5bb932cfca':

* commit 'b88c1729d89e76b06ae3b87d90cae6ea36cfde90':

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am e2cbcf38: am 72fa49d4: am bb971d53: Merge "Implement hashCode() and equals() behind a generator option."

* commit 'e2cbcf3853917c6ce1fcc0cbcc00b747db7798fe':

am 0610e683: am 7cb6b37f: am 42be1e79: Merge "Feature request: set() and clear() accessors return this"

* commit '0610e6834fa213c026d91fab037a649613840f44':

am 4b359335: am d52f7a3e: am c50f605c: Merge "Make generated code more aligned with Google Java style."

* commit '4b359335e94c44fa16b78c1406f3cd71b7fbf40b':

* commit '677d51bb86ca57654617dae9fe645995a1b22658':

* commit '8f903e123aff94f272aaae22e275924980433a47':

am 0e5add1d: am 051ea13c: am c85806ba: Merge remote-tracking branch \'goog/klp-dev-plus-aosp\' into tomerge

* commit '0e5add1dd4a5ce73ff10b38307bae942be178d5b':

am ee8847c1: am 145af9e8: am 39cee9f1: Merge "Remove all field initializers and let ctor call clear()."

* commit 'ee8847c131e91c718a0f4d2af73ec56d9fd24d81':

am dc8f4a8b: am 7457ebc9: am cbb08132: Merge "Add missing README parts for enum_style and in-repo usage"

* commit 'dc8f4a8bc871cf1ba6a27eaf7f581a144571411a':

* commit 'ca07ad9d617b3ebab5d66077413bdfc7673a2926':

* commit 'd6be7db044050f9941ff7b7a3e57af0565d4e53c':

am 5f8ef515: am 0255eb04: am 9827c718: Merge "Fix roundtrip failure with groups when unknown fields are enabled."

* commit '5f8ef51529f07ae758ec4944759828a1414dbb7c':

* commit 'c1f9ebcefb026a84e369347ddc23a3e4c6e9c940':

* commit 'c017bb8c147d30641b36e6d16b9133c0dd9e8453':

* commit '6778e0a0198f602cab76daf6428a97292007dc71':

* commit 'bbda8b10152bbdb7d6057724f0e3e197db9ec108':

* commit '380d1b5a78de07a081b36c890321ac61a0fced1a':
  Fix the merge conflict leftovers.

* commit 'adfb09a08d450f356a69c74c0a80a3e4573e20b8':

am df9a6dff: am 48ee66d2: am ece98e5f: Merge "Fix checkbuild targets, remove unittest_enum_mulitplejava_nano.proto."

* commit 'df9a6dffee90f5ff657265b415ee5eb9fb5e3960':

* commit 'ba363f1380e9b99e6606462b21febd2e4027e340':

am 4d7f9ad7: am ece98e5f: Merge "Fix checkbuild targets, remove unittest_enum_mulitplejava_nano.proto."

* commit '4d7f9ad71771fff628e88d463af94b44457b7934':

* commit 'f105476adedac50be509ed36cbb187b92fca54d9':

* commit '94f522f907e3f34f70d9e7816b947e62fddbb267':
  You CANNOT change the global WITH_DEXPREOPT

* commit '49512cb01065b41c0113248c2c02800de1156d50':
  You CANNOT change the global WITH_DEXPREOPT

Bug: 14380196
Change-Id: I2b9e6db081558687afd5c20c7084824dfe1bb26e

* commit '58eb8e98d17971273548930a7e8d45e69995a2c8':
  Fix NPE when clearing an extension in nano protos

* commit 'd20f0a4260763531acf5de677e4830afe0bfc53e':
  Fix NPE when clearing an extension in nano protos

If ExtendableMessageNano doesn't have any unknown fields, trying to
clear an extension by setting it to null would throw an NPE.

Change-Id: I6abcdfcc0193de44f97b21dd6cc2f40604938a1a